How is product quality control carried out? Quality control of finished products

Types of quality control

Solid

Selective

Incoming control

Interoperational control

More accurate classification

Quality Management System Certification

Certification- a procedure confirming by a third party the compliance of a product, process or service with specified requirements and issued in the form of a written guarantee.

The quality management system in ISO 9000 standards is understood as part of the enterprise management system, based on documented procedures for managing and executing business processes.

ISO 9000 is a series of international standards for creating a quality management system.

Certification of quality management systems is a highly effective market tool, since a certificate issued by a reputable organization is recognized as tangible evidence of the quality that the consumer (customer) has the right to expect.

The formulation of modern quality management presupposes that the enterprise must carry out a systemic restructuring of its activities, affecting tasks that, to one degree or another, rely on the principles of quality management laid down in the ISO 9000 series standards (strategy, structure, processes, personnel).

The certification procedure aims to give the manufacturer of the relevant products a license to use the mark of conformity.

In Russia, in accordance with the Law on Certification of Products and Services, a state product certification system has been created, which operates under the leadership of Gosstandart of Russia as the national certification body. The national standard describing the QMS certification procedure is GOST R 40.003. This system complies with ISO rules.

The basis for certification in terms of human safety and environmental protection are domestic or foreign standards.

Having a certified system allows an enterprise to:

1. reduce unproductive costs (production losses);

2. improve the level of quality of products or services;

3. be more competitive;

4. improve the organizational management structure and increase its efficiency;

5. increase product sales;

6. sell manufactured products on the international market;

7. the possibility of obtaining preferential loans;

8. receive a state, municipal, or city order for the production of works and services;

9. form public opinion about the stable position of the enterprise in the market.

Question 28. Fixed assets: concept, composition, structure. Basic production and non-production assets. Depreciation and reproduction of fixed production assets. Depreciation and methods of its calculation.

Fixed assets – These are tangible assets (implements of labor) that are repeatedly involved in the production process, do not change their natural material form and transfer their value to the finished product in parts as they wear out.

Classification of fixed assets.

1. By purpose and scope of application:

Basic production assets;

Basic non-production assets.

2. By degree of use:

Fixed assets in operation;

Fixed assets in reserve;

Those in the stage of completion, reconstruction, partial liquidation;

Preserved.

3. Depending on existing rights to property:

Objects owned by an enterprise;

Objects under operational management or economic management;

Objects received for rent.

4. According to natural composition:

Facilities;

Transfer devices;

Cars and equipment;

Vehicles;

Tools, production and household equipment

Based on the degree of participation in the production process, fixed assets are divided into active and passive. Active part(machinery, equipment) directly affects the production, quantity and quality of products (services). Passive elements (buildings, structures, transport) create the necessary conditions for the production process.

Types of quality control

Thus, a distinction is made between sample, continuous and statistical types. Solid All products undergo inspection. During continuous control in production, records are kept of all defects that arise during the manufacturing process of the product.

Selective- control of a part of the product, the inspection results of which apply to the entire batch. This type is precautionary, hence it is carried out throughout production process in order to prevent marriage.

The process of product quality control at enterprises is carried out by the technical control department (QC) or the quality control department.

Incoming control- checking the quality of raw materials and auxiliary materials entering production. Constant analysis of supplied raw materials and supplies allows us to influence the production of supplier enterprises, achieving improved quality.

Interoperational control covers all technological process. This type is sometimes called technological, or current. The purpose of interoperational control is to check compliance with technological regimes, rules of storage and packaging of products between operations.

Output (acceptance) control- quality control finished products. The purpose of final control is to establish compliance of the quality of finished products with the requirements of standards or technical specifications, identifying possible defects. If all conditions are met, then delivery of the product is permitted. The quality control department also checks the quality of packaging and the correct labeling of finished products.

More accurate classification

Factors affecting product quality

At each enterprise, the quality of products is influenced by various factors, both internal and external.

Internal ones include those that are related to the enterprise’s ability to produce products of appropriate quality, i.e. depend on the activities of the enterprise itself. They are numerous, they are classified into the following groups: technical, organizational, economic, socio-psychological.

Technical factors most significantly influence the quality of products, therefore the introduction of new technology, the use of new materials, and higher quality raw materials are the material basis for the production of competitive products.

Organizational factors are associated with improving the organization of production and labor, increasing production discipline and responsibility for product quality, ensuring production culture and an appropriate level of personnel qualifications.

Economic factors are determined by the costs of production and sales of products, pricing policies and the system of economic incentives for personnel for the production of high-quality products.

Socio-economic factors significantly influence the creation of healthy working conditions, loyalty and pride in the brand of one’s enterprise, moral stimulation of workers - all these are important components for the production of competitive products.

External factors in the conditions market relations contribute to the formation of product quality. The external or environment is an integral condition for the existence of any enterprise and is an uncontrollable factor in relation to it. All impact external environment can be divided into the following individual factors: economic, political, market, technological, competitive, international and social.

Analyzing the external environment enables an organization to forecast its capabilities, to make a contingency plan, to develop an early warning system against possible threats and to develop strategies that could turn external threats into any profitable opportunities. Analysis of the external environment is necessary in the strategic planning process.

Among the environmental factors considered, competitive factors occupy a special place. No organization can afford to ignore the actual or potential reactions of its competitors.

In the conditions of market relations, the goals of the enterprise change, which combine the following issues: ensuring survival, maximizing load, maximizing current profits, gaining leadership in the market segment, gaining leadership in terms of product quality, achieving a specific sales volume, growing sales, winning the favor of the client.

Product quality control at enterprises is carried out by the technical control department (QC). Product quality control is divided into three types: input, interoperational and output (acceptance).

· Incoming control - checking the quality of raw materials and auxiliary materials entering production. Constant analysis of the quality of supplied raw materials allows us to influence the production of supplier enterprises, achieving improved quality.

· Interoperational control covers the entire technological process. This control is sometimes called technological or current control. The purpose of interoperational control is to verify compliance with technological regimes, rules of storage and packaging of products between operations.

· Output (acceptance) control - quality control of finished products. The purpose of final inspection is to establish compliance of the quality of finished products with the requirements of standards or technical specifications, and to identify possible defects. If all conditions are met, delivery of the product is permitted.

The quality control department also checks the quality of packaging and the correct labeling of finished products. Input, interoperational and output control can be selective, continuous and statistical.

· Selective - control of a part of the product, the results of which apply to the entire batch.

· All products are subject to continuous control (in undeveloped technological conditions).

· Statistical control - preventive. It is carried out throughout the entire technological process in order to prevent defects.

Requirements for the quality of industrial products: organoleptic properties. Product quality is formed at the product development stage and is accompanied by regulatory and technical documentation. Product quality must be ensured at all stages of production and maintained at the stages of storage, transportation and sales.

When raw materials or semi-finished products arrive at the enterprise, the first thing they look at is their appearance. Are there any cracks or dents on the surface, is the product in the correct shape, is the packaging intact, and does the manufacturing date match? Sometimes suitability is determined by smell. Odors that are not characteristic of the product are the result of violations of the preparation technology or spoilage during storage.

One of the main indicators of the quality of raw materials and semi-finished products is their consistency. The very concept of consistency includes the characteristic state of aggregation(solid, liquid), degree of homogeneity (curdled, flaky, lumpy, homogeneous), mechanical properties (brittle, elastic, plastic, elastic, brittle). The consistency is determined visually (foamy, liquid) and using the organs of touch.

Organoleptic assessment of raw materials and semi-finished products can give accurate results, provided that the rules are followed and the rules are followed. The amount of raw materials and semi-finished products should be small, since under the influence of fatigue the impressionability of the senses quickly decreases, and they also become accustomed to a certain stimulus.

Sanitary rules, which determine the conditions and shelf life of highly perishable products, are intended for all enterprises producing and selling highly perishable products.

Particularly perishable products include products that cannot be stored without refrigeration, and the maximum shelf life is at a temperature not exceeding +6 degrees. If storage conditions and periods are violated, microorganisms that cause spoilage of products, as well as microorganisms that can cause bacterial food poisoning and acute intestinal diseases, can multiply in them.

For each batch of particularly perishable products, the manufacturing enterprise must issue documents certifying the quality (certificate), an invoice (collection sheet) indicating the date and hour of production of the product at the enterprise from the end of the technological process, the storage temperature and the end of its shelf life (date, hour) in accordance with these Rules.

Transportation of particularly perishable products must be carried out in closed, labeled containers by refrigerated or insulated vehicles with bodies that have a hygienic coating. Local sanitary and epidemiological stations must issue sanitary passports for each vehicle transporting particularly perishable products. IN warm time transportation is carried out in isothermal transport in the presence of ice - no more than 3 hours, without ice - no more than 1 hour.

Storage of particularly perishable products in trade and public catering establishments is permitted subject to compliance with temperature regime from +2 to +6 C. The exception is some semi-finished and finished products, the storage temperature of which is indicated in the list.

Cold dishes and snacks are perishable items, so they should be prepared in small portions and sold quickly, since storage sharply worsens their taste and appearance.

Cold dishes and snacks, as well as semi-finished products for them, should be stored in refrigerated cabinets at a temperature of 0...6 °C and relative humidity air 75...85%. They should be stored in porcelain or enamel dishes(without cracks or broken enamel), closed with a lid or dry gauze.

Roast beef, ham, poultry, game are stored on dishes or baking sheets, salmon, balyk, sturgeon and similar products are stored on marked dry boards under dry gauze. It is recommended to cut food before serving.

Semi-finished meat, capital and fish salads, as well as salads from sauerkraut, manufactured at procurement factories, can be stored at a temperature of 4...8 ° C for 12 hours.

NON-STATE EDUCATIONAL INSTITUTION OF HIGHER PROFESSIONAL EDUCATION

"YELABUGA CITY INSTITUTE OF INNOVATIVE TECHNOLOGIES"

Faculty of Engineering and Technology

Department of Quality Management

Test

in the discipline: “Means and methods of quality management”

on the topic: “Incoming product quality control”

Yelabuga 2011

Introduction

Concept and types of product quality control

Incoming product quality control, definition, concept of purpose, main tasks, organization of incoming control, efficiency

Conclusion

Introduction

Relevance. Quality control is one of the main functions in the quality management process. This is also the most voluminous function in terms of the methods used, which are the subject of a large number of works in different areas knowledge. The importance of control lies in the fact that it allows you to identify errors in time, so that you can quickly correct them with minimal losses.

The purpose of this work is to consider quality control, as well as to define the concept of incoming product quality control, its purpose, main tasks, organization of incoming control and efficiency.

The test consists of an introduction, 4 chapters, a conclusion, where all the conclusions of the work and a list of references are summed up.

The first chapter discusses the concept and types of product quality control. The second chapter discusses incoming product quality control, definition, concept. The purpose, main tasks, organization and effectiveness of incoming product quality control are discussed in the third chapter. And how incoming quality control of metal products is carried out at enterprises is discussed in the fourth chapter.

quality control standard metal products

1. Concept and types of product quality control

Quality control means checking the compliance of the quantitative or qualitative characteristics of a product or process on which the quality of the product depends, established technical requirements.

Product quality control is integral part production process and is aimed at checking reliability during its manufacture, consumption or operation.

The essence of product quality control at an enterprise is to obtain information about the condition of the object and compare the results obtained with the established requirements recorded in drawings, standards, supply contracts, technical specifications. NTD, TU and other documents.

Control involves checking products at the very beginning of the production process and during operational maintenance, ensuring in case of deviation from the regulated quality requirements, the adoption of corrective measures aimed at producing products of adequate quality, proper Maintenance during operation and complete satisfaction of consumer requirements. Thus, product control includes such measures at the place of its manufacture or at the place of its operation, as a result of which deviations from the norm of the required level of quality can be corrected even before defective products or products that do not meet technical requirements are released. Insufficient control at the stage of manufacturing serial products leads to the emergence of financial problems and entails additional costs. Quality control includes:

incoming quality control of raw materials, basic and auxiliary materials, semi-finished products, components, tools arriving at the enterprise’s warehouses;

operational production control over compliance with the established technological regime, and sometimes inter-operational acceptance of products;

systematic monitoring of the condition of equipment, machines, cutting and measuring tools, instrumentation, various measuring instruments, dies, models of testing equipment and weighing facilities, new and in-use devices, conditions of production and transportation of products and other checks;

control of models and prototypes;

control of finished products (parts, small assembly units, subassemblies, assemblies, blocks, products).

Incoming product quality control, definition, concept

purpose, main tasks, organization of incoming control,

efficiency

Incoming product quality control should be understood as quality control of the supplier’s products received by the consumer or customer and intended for use in the manufacture, repair or operation of products.

These recommendations establish the basic provisions for organizing, conducting and processing the results of incoming inspection of raw materials, materials, semi-finished products, components, etc., coming from suppliers to consumers.

The recommendations were developed to provide methodological and practical assistance to enterprise specialists in the implementation and use of a product quality management system based on the application of international standards ISO 9000 series.

The main tasks of incoming control can be:

obtaining with high reliability an assessment of the quality of products submitted for control;

ensuring the unambiguous mutual recognition of the results of product quality assessment by the supplier and the consumer, carried out using the same methods and the same control plans;

establishing compliance of product quality with established requirements in order to timely submit claims to suppliers, as well as to promptly work with suppliers to ensure the required level of product quality;

preventing the launch into production or repair of products that do not meet established requirements, as well as permitting protocols in accordance with GOST 2.124. [GOST]

One of the elements of the relationship with the supplier is the organization of incoming control, which means quality control of the supplier’s products ( starting materials, components, information) received by the consumer organization and intended for use in the manufacture, repair or operation of products, as well as the provision of services. Its main goal is to exclude the possibility of penetration into production of raw materials, materials, semi-finished products, components, tools, information with deviations from the quality requirements reflected in contractual obligations. Imperfections in this type of control can bring significant losses to both the product manufacturer and its consumer.

Incoming control is very labor-intensive and expensive, and it duplicates the output control of the manufacturing enterprise. In this regard, it is becoming increasingly important to abandon incoming control by strengthening output control, which entails the establishment of special relationships with the supplier. The practice of such relations has existed abroad for a long time. For example, at the Japanese company Bridgestone Corporation, supplied parts and raw materials are inspected mainly to check their quantity and compliance with technical documentation. The quality of materials is not checked, as it is carried out by suppliers before sending them to the consumer. This system is based on mutual trust and cooperation.

In accordance with the terms of the supply agreement, incoming inspection can be either continuous or selective. To implement it at industrial enterprises, specialized units are created in the quality control system. Medium and large enterprises operate incoming control laboratories. The main tasks of these units are:

Carrying out incoming quality control of material and technical resources entering the organization;

preparation of documents based on control results;

control of technological tests (samples, analyses) of incoming resources in workshops, laboratories, control and testing stations;

monitoring compliance by warehouse workers with the rules of storage and release of incoming products into production;

calling representatives of suppliers to jointly draw up a report on defects detected during incoming inspection, etc. Demonstration of the effectiveness of incoming control is the reduction of cases of low-quality material and technical resources or services entering production.

Forms of incoming control include:

Periodic monitoring of the effectiveness of the supplier’s quality assurance system (the so-called “second party” audit);

The requirement for the supplier to accompany the shipment of goods with protocols of control procedures;

The requirement for the supplier to carry out 100% control and testing of the supplied material and technical resources or services;

Selective acceptance testing of a batch of goods by the supplier and consumer simultaneously;

The supplier's use of a formal quality assurance system defined by the customer (for example, based on ISO 9000 standards);

Requirements for independent third party certification of supplier products.

If we are guided by the international standard ISO 9001:2008, then in section 7 “Manufacture of products” in subsection 7.4 “Purchases”, paragraph 7.4.1 states: “The organization must ensure that purchased products comply with established procurement requirements. The scope and nature of control over the supplier and purchased products should be determined by the degree of influence of these products on subsequent production of the product or on the finished product.”

The organization shall evaluate and select suppliers based on their ability to provide products in accordance with the Organization's requirements.

Criteria for selecting, evaluating and re-evaluating suppliers must be established. Records should be kept of the results of this assessment and subsequent actions.”

In clause 7.4.2 “Purchasing Information” we read: “Purchasing information must contain a description of the products being ordered and include, where necessary:

requirements for approval of products, procedures, processes and equipment;

requirements for personnel qualifications;

requirements for the quality management system.

The organization must ensure that specified purchasing requirements are adequate before communicating them to the supplier.

And finally, paragraph 7.4.3 “Checking (verification) of purchased products is as follows: “The organization must determine and implement control measures or other activities necessary to ensure compliance of purchased products with the requirements specified in the procurement information. In cases where the Organization or its consumer intends to check (verify) purchased products at the supplier’s enterprise, the Organization must establish in the procurement information the intended measures for such verification and the method of product release.”

Incoming quality control of metal products

The main indicators of metal quality are: chemical composition; micro- and macrostructure; basic and technological properties; dimensions, geometry and surface quality of metal products. Requirements for the quality of metal and products made from it are specified in national standards, technical conditions of companies (enterprises) or separate agreements between the consumer and the supplier. The quality of the metal and reliable methods for determining its main indicators are the main ones in the technological production chain. The quality of metal products entering the enterprise is determined during incoming inspection (IC).

Incoming inspection of metal products is mandatory at companies (enterprises) that develop or manufacture industrial products, as well as repair them. This control is organized and carried out in accordance with GOST 24297-87, as well as with standards and other regulatory and technical documentation (NTD) of the enterprise.

Organization of incoming quality control of metal products:

In accordance with GOST 24297-87, incoming inspection is carried out by an incoming inspection unit - the incoming inspection bureau (IBK), which is part of the enterprise's technical quality control (QC) service.

The main tasks of incoming control are:

monitoring the availability of accompanying documentation for products;

control of compliance of the quality and completeness of products with the requirements of design and regulatory technical documentation;

accumulation of statistical data on the actual level of quality of the resulting products and development on this basis of proposals to improve the quality and, if necessary, revise the requirements of the technical documentation for products;

periodic monitoring of compliance with the rules and shelf life of suppliers’ products.

Incoming inspection must be carried out in a specially designated room (area) equipped necessary means control, testing and office equipment, as well as meeting occupational safety requirements. Measuring instruments and testing equipment used during incoming inspection are selected in accordance with the requirements of the normative and technical documentation for controlled products and GOST 8.002-86. If metrological means and control methods differ from those specified in the technical documentation, then the consumer agrees specifications the means and methods of control used with the supplier.

To ensure compliance with the requirements of GOST 24297, as well as the standards of the GOST R ISO 9000 series, the enterprise is developing its own technical documentation, taking into account the profile and characteristics of the products. For example, large enterprises are developing enterprise standards (STP) “Incoming control metal materials», « Technological instructions(TI) of incoming inspection of metallic materials”, etc.

STP establishes the procedure for organizing, conducting and recording the results of incoming inspection of metal products used at the enterprise. TI determines the scope and types of incoming inspection in accordance with the list of metals and semi-finished products subject to inspection. The scope and types of incoming inspection are established in accordance with the normative and technical documentation and technical specifications for manufactured products.

Conducting the VC is entrusted to the BVK. Input control involves: a warehouse of purchased metal products or a consumer workshop (hereinafter referred to as the warehouse) and the central factory laboratory(TsZL).

Incoming inspection of metal products includes the following checks:

accompanying documentation certifying quality (certificate, passport);

labeling, containers, packaging;

geometric dimensions;

surface conditions;

special properties;

brand of material (chemical composition), mechanical properties, structures.

A typical scheme for organizing a VC (Fig. 3.1) is as follows. Metal products received at the warehouse are accepted with accompanying documentation on nomenclature, assortment and quantity and no later than 10 days are transferred for incoming control. At the incoming inspection, checks are carried out on the first four points (see above) and samples are taken to confirm the metal grade, structure, mechanical and special properties. Sampling is carried out under the control of the BVK. Selected samples are transferred to the Central Laboratory. Based on the incoming inspection data, including the conclusions of the central laboratory, a conclusion is made about the compliance of the quality of metal products with the established requirements.

Rice. 3.1. Typical scheme for organizing incoming control

At positive results control in the accompanying documentation (certificate, passport) a note is made “Incoming control has been carried out, complies with technical specifications”

If any indicator does not meet the established requirements, twice the number of samples from a given batch of metal is subjected to control. If unsatisfactory results are received again, the warehouse, BVK and the supply department draw up a defect report.

Rejected metal is marked with red “Reject” paint and stored in a reject isolator until a decision is made on disposal or return.

Control of geometric dimensions. The TI regulates the scope of control over the size of the assortment of metal products, which is, as a rule, 5% of one batch. Dimensions are controlled using measuring instruments that provide a measurement error equal to ½ tolerance on the measured parameter.

Depending on the type of assortment (rod, strip, sheet, etc.), the dimensions specified in the certificate are subject to control, while the technical specifications stipulate how and in what places measurements are taken.

For example, the thickness of strips and tapes should be measured at a distance of at least 50 mm from the end and at least 10 mm from the edge. Tapes with a width of 20 mm or less are measured in the middle. Measurements are made with a micrometer in accordance with GOST 6507-90 or GOST 4381-87.

The thickness of sheets and plates is measured at a distance of at least 115 mm from the corners and at least 25 mm from the edges of the sheet using a caliper (GOST 166-89).

The diameters of rods and wires are measured in at least two places in two mutually perpendicular directions of the same section using a micrometer (wire) or a caliper (rod). Width and length are measured with a metal tape measure in accordance with GOST 7502-89 or a metal ruler in accordance with GOST 427-75.

Surface control. The quality of the metal surface is checked for compliance with the requirements of the normative and technical documentation for delivery visually without the use of magnifying devices (except for cases specifically stated). The recommended amount of inspection is 5% of the lot. In some cases (forgings, castings, etc.), 100% of the product is subjected to surface control.

The most common characteristic surface defects of metal products are given in table. 3.1 and in Fig. 3.2.

Table 3.1 Surface defects of metal products

Name of defect Types, origin and a brief description of defect The influence of a defect on the quality of a semi-finished product or finished product Metallurgical defects Films (Fig. 3.2, a) During pressure treatment, the walls of bubbles and shells of ingots are compressed, stretched and partially broadened. As the compression of the metal increases, the outer walls of the chambers become thin and break through. The delamination of metal formed in this way, more or less parallel to the surface and extending onto it, is called film. Removing film on semi-finished products, if their depth does not exceed the dimensional tolerances, does not affect the quality of the product. Films on the surface of the tubes lead to the rejection of products Cracks (Fig. 3.2, c, d, f, g) Cracks on the surface, as well as internal cracks, are the result of stresses arising from uneven heating, strong hardening, burns during grinding and similar reasons Cracks, that do not take the semi-finished product beyond the dimensional tolerances are classified as correctable defects. In the finished product, cracks cause rejection Bubbles (Fig. 3.2, b) If the outer wall of the finished bubble is very thin, then when the metal is heated, the gases inside the bubble expand, bulge the outer wall and form a bubble on the surface of the Shells Shells on the surface of the castings are the result of unsatisfactory molding, cutting out defects , and in products obtained by pressure treatment, as a result of opened bubbles, etc. If the sink does not take the size of the product beyond the limits established tolerances, semi-finished products with surface cavities are considered a correctable defect. In finished products, cavities lead to rejection. Burrs and declines. A burr is a convexity along a rolled profile, resulting from the extrusion of metal from the stream into the gap between the rolls. A burr is a burr rolled into metal during finishing rolling. Burrs are also found on stamped workpieces when the halves of the trimming die are displaced. Finished rods and rods of profile metal in the presence of a burr or sunset are rejected. great strength friction arising during the drawing process, accompanied by strong vibration. Ringiness on finished tubes leads to their rejection. White spots and stripes. White spots and stripes are defects found mainly on aluminum products. They are a consequence of contamination of the metal with electrolyte, the presence of non-metallic inclusions and impurities of sodium and calcium. The defect sharply reduces the corrosion resistance of aluminum and aluminum products, and also spoils their appearance. Natrium disease Natrium disease - inclusions of sodium compounds in aluminum. products caused by sticking of aluminum to rolling rolls. Chemical defects. Over-etching Over-etching is characterized by a rough surface that reveals the crystalline structure of the metal. Severe overetching in thin-walled products leads to a significant reduction in the cross-section of the walls. Over-etching is a consequence of a high concentration of etching substances, as well as long exposure of products in them. Under-grasses Under-grasses are dark spots or uneven shade of the surface. Under-etching is the result of etching with solutions of weak acids and alkalis or exhaustion of the bath, short exposure in the bath, as well as contact of products with each other during etching. Haze is the result of uneven etching caused by oil contamination during stamping, segregation heterogeneity, etc. Rough spots Rough dark and white spots on products made of light metals indicate corrosion Mechanical defects Risks and scratches Risks (longitudinal scratches) occur on internal and external surfaces as a result of poor polishing of the dies, the ingress of solid particles into them (sand, scale, metal shavings), and the ingress of the same particles into the drawing point when broaching, with non-smooth surfaces of profiles, matrices, etc. Scores are obtained as a result of pressing at high temperatures or at high pressing speeds Defects spoil the appearance, reduce the dimensional accuracy of manufactured products, and sometimes lead to defects Flaws and tears Flaws and tears are the result of the rigidity of the metal, defects of the stamping tool ( sharp corners) And incorrect installation stamps Leads the product to defects Wrinkles and folds Most often found on the bodies of drawn products and are vertically located thickenings from metal compression. These defects arise as a result of uneven thickness of the workpiece or the gap between the dies and insufficient preheating of the workpiece. They spoil the appearance and lead to defects in the finished product. processing with abrasive tools Reduces the service life of the product and spoils the appearance of the surface. Snags on the cutting part of the tool reduce the quality of its work. Grooves. Grooves are lines visible to the naked eye and running in the direction of rough grinding on finished products (tools). Grooves spoil the appearance, reduce corrosion resistance, and in some devices and tools affect proper operation. Peeling of metal or non-metallic parts. coatings Peeling of metal and non-metallic coatings is the result of their poor adhesion to the base metal. Nicks (Fig. 3.2, e)

Rice. 3.2. Surface defects of metal products: a) films; b) bubbles on the surface; c) cracks due to strong hardening; d) crack caused by grinding burn; e) nicks; f) hardening cracks; g) grinding cracks; (f and g - revealed by magnetic powder)

If it is necessary to control the inner surface of pipes, samples are cut from them, cut along the generatrix and the presence of defects is checked. In all cases, when defects are detected (including traces of corrosion), samples are taken from the locations of these defects and sent to the Central Laboratory to determine the nature of the defect and the depth of its occurrence. Based on the conclusion of the central laboratory, a decision is made on the suitability of a given batch of metal.

Control of chemical composition and mechanical properties. This control is carried out in the central laboratory on specially selected samples from each batch of metal with a conclusion drawn up in the prescribed form.

Chemical composition control. This type control is carried out in order to establish compliance of the qualitative and quantitative chemical composition of metal products with the standards stated in the certificate.

The sampling rate for monitoring the chemical composition is established in the technical specifications and is usually:

for sheets and slabs - from one control sheet, batch slab;

for tapes, strips, wire - from one control roll of the batch;

for rods and profiles that are individually stamped by the supplier - from one rod, profile, batch;

for rods and profiles marked on a tag - from 2, 3 and 5 rods, profiles for batches of less than 30 pcs., from 30 to 50 pcs. and over 50 pieces respectively.

The selected samples are sent to the central laboratory, where the chemical composition is monitored using chemical and/or spectral methods analysis.

Chemical methods analyzes based on the chemical reactions of analytes in solutions include mainly gravimetric, titrimetric and colorimetric analyses. These methods are described in the relevant GOSTs. It should be noted that chemical analysis is labor-intensive, not universal, and does not have high sensitivity (especially at low concentrations of the elements being determined).

Spectral analysis - physical method qualitative and quantitative determination of the composition of a substance from its spectra.

For express and marking analysis of the chemical composition of steels, cast irons and non-ferrous alloys, spectrographs (ISP-30, DFS-13, DFS-8) and quantometers (DFS-41, DFS-51, MFS-4, “Papuas-4”) are widely used. , the basis of which is the generally accepted scheme of emission spectral analysis. When performing an analysis, a pulsed electric discharge is excited between two electrodes, one of which is the sample being analyzed. Radiation from the atoms of the elements that make up the sample, excited in the discharge, passes through a polychromator with a concave diffraction grating and is decomposed into a spectrum. To each chemical element corresponds to its own set of spectral lines, the intensity of which depends on the concentration of the element in the sample.

At qualitative analysis the resulting spectrum is interpreted using tables and atlases of the spectra of elements. For quantitative analysis of a sample, one or more analytical lines of each analyzed element are selected from the spectrum.

The intensity (J) of a spectral line of length l is related to the concentration (c) of the element in the sample by the dependence:

(l) = a × сb,

where a and b are quantities depending on the analysis conditions.

Modern devices for spectral analysis, as a rule, they are combined with a computer, which makes it possible to fully automate the analysis of spectra. In addition to the indicated devices, enterprises use steeloscopes (Fig. 3.3) of the “Spectrum” type for rapid visual qualitative and comparative quantitative analysis of ferrous and non-ferrous alloys in the visible region of the spectrum. The portable version of the steeloscope (SLV) allows such analysis to be carried out in workshops, warehouses, and on large parts without destroying the surface.

Spectral analysis of metals is carried out according to GOST standards, namely:

steels - GOST 18895-81;

titanium alloys - GOST 23902-79;

aluminum alloys - GOST 7727-75;

magnesium alloys - GOST 7728-79;

copper - GOST 9717.1-82, GOST 9717.2-82, GOST 9717.2-83;

copper-zinc alloys - GOST 9716.0-79, GOST 9716.1-79, GOST 9716.2-79, GOST 9716.3-79;

tin-free bronzes - GOST 20068.0-79, GOST 20068.1-79, GOST 20068.2-79, GOST 20068.3-79.

X-ray spectral analysis. Compared to optical spectra, X-ray characteristic spectra contain fewer lines, which simplifies their interpretation. This advantage is driving the increasing use of X-ray analysis in factory laboratories.

The characteristic X-ray spectrum of a sample can be obtained either by placing it on the anode of an X-ray tube and irradiating it with an electron beam with an energy of 3-50 KeV (emission method), or by placing the sample outside the tube and irradiating it with sufficiently hard X-rays emanating from the tube (fluorescence method).

The fluorescent method is more preferable because:

has a higher sensitivity (up to 0.0005%);

more efficient and technologically advanced (there is no need to make the tube dismountable and pump it out to maintain the vacuum);

the sample is not heated.

Fluorescent X-ray spectrometers used in industry to control the chemical composition of steels and alloys (Spark-1-2M, Lab-X3000, ED 2000, MDX 1000) are equipped with a computer, which allows you to automate the process of processing spectra and increase efficiency (Fig. 3.4).

The results of control of the chemical composition of the metal are documented in the accompanying documentation and registered in the incoming control passport.

Rice. 3.3. Optical diagram of the steeloscope: 1 - light source (electric arc between the electrodes, which serve as the samples under study); 2 - capacitor; 3 - slot; 4 - rotary prism; 5 - lens; 6 and 7 - prisms that decompose light into a spectrum; 8 - eyepiece

Rice. 3.4. Functional diagram of a fluorescent X-ray spectrometer: RT - X-ray tube; A - analyzer; D - detector

During the incoming inspection of imported materials, the grade of the material is determined in accordance with the certificate chemical composition.

Control of mechanical properties. This type of control is carried out at the Central Plant in accordance with the requirements of STP and TI. The content and scope of control of the mechanical properties of metal products supplied to the enterprise are determined by the grade of metal, delivery condition and purpose in accordance with the normative and technical documentation.

As a rule, mechanical properties are controlled by tests: uniaxial tensile, hardness, impact strength(see Chapter 2). The shape and dimensions of test samples must comply with the requirements of GOST 1497-84 and GOST 9454-78.

For tensile testing of round, square and hexagonal metal, 2 samples, 60 mm long from either end of the rolled product, are taken from each batch.

For tensile testing of wire supplied in coils for the manufacture of springs, a sample 600 mm long is taken from one coil of each batch, and for wire with a diameter 0.9 mm one sample 1500 mm long at a distance of at least 1 m from the end of the coil.

For tensile testing of rolled sheets, two samples 250 mm long and 50 mm wide are taken from one sheet along the rolling direction, and from sheets of aluminum and magnesium alloys - across the rolling direction. For tapes and strips, a sample 400 mm long is taken from one roll of each batch at a distance of at least 1 m from the end of the roll.

To test the impact strength of sheets, strips with a thickness of at least 11 mm, pipes with a wall thickness of at least 14 mm, rods with a diameter of at least 16 mm, 2 samples of size 11 are taken from either end next to the tensile test sample × 11× 60 mm for making samples size 10 × 10× 55 mm. From rolled products with a thickness of up to 10 mm, 2 samples are taken to make samples of size 5 × 10× 55 mm. To test impact strength at sub-zero temperatures, 3 samples are taken.

If results are obtained that do not comply with the certificate, the test is repeated on twice the number of samples. If repeated tests yield negative results on at least one sample, then the entire batch of metal is rejected. The results of the mechanical properties of the metal are reflected in the incoming inspection passport with test tables attached.

Conclusion

In the global market into which the Russian economy is integrating, enterprises need management that provides advantages over competitors in terms of quality criteria. Gradually, the understanding comes that to produce products of the required quality, it is no longer enough to have a technical control department.

In order to increase their competitiveness, an increasing number of enterprises are realizing the need to create a quality management system and certify it for compliance with the requirements of international standards.

Having studied the topic “Quality Management”, we found out that the direct management of the quality management system is carried out by an authorized person, and that his responsibilities include:

ensuring the development, implementation and maintenance of a quality management system;

control over the implementation internal audits quality management system, analysis of its effectiveness;

submitting reports to the director on the functioning of the quality management system, analyzing its effectiveness.

We also found out that operational activities related to the functioning of the quality management system are carried out by a specially created quality service, whose tasks include:

coordination of work and direct participation in the development, implementation and operation of the quality management system;

creation of a database on the quality management system;

organizing accounting and monitoring the implementation of measures and documents of the quality management system, conducting internal audits;

improvement of the quality management system.

Under the new requirements, the organization must establish and detail product/service measurement requirements, including acceptance criteria. Measurement must be planned to confirm their compliance with the detailed requirements. The organization should plan to use statistical methods to analyze data. In problem analysis, causes must be identified before corrective or preventive actions can be planned. Information and data from all parts of the organization must be integrated and analyzed to assess the overall performance status of the organization. Based on objective information, methods and means for continuous process improvement are determined.

Effective functioning of the quality system involves the creation and operation of an information retrieval system, corrective actions and results obtained in the field of quality.

Having a certified quality system at an enterprise is not an end in itself. Firstly, a number of industries have their own specific certification systems. Secondly, ISO 9000 certification is a necessary but not sufficient element of competitiveness. And thirdly, recognized leaders of the market economy create their own, more developed and advanced quality management systems. But there is no doubt that the absence of an appropriate quality system deprives an enterprise of the prospect of surviving in conditions of fierce competition.

List of used literature

1. Rebrin Yu.I. Quality control: Tutorial. Taganrog: TRTU Publishing House, 2004. 174 p.

Great Soviet Library, TSB; #"justify">. Gludkin O.P. Methods and devices for testing RES and EVS. - M.: Higher. School., 2001 - 335 p.

Unofficial GOST website; #"justify">. Build Consultant; #"justify">. A.I. Orlov Mathematics of chance: Probability and statistics - basic facts: Textbook. M.: MZ-Press, 2004, - 110 p.

V.G. Shipsha. Lecture: Incoming quality control of metal products.

Product quality control at enterprises is carried out by the technical control department (QC).

Product quality control is divided into three types: input, interoperational and output (acceptance).

Incoming control- checking the quality of raw materials and auxiliary materials entering production. Constant analysis of the quality of supplied raw materials allows us to influence the production of supplier enterprises, achieving improved quality.

Interoperational control covers the entire technological process. This control is sometimes called technological or current control. The purpose of interoperational control is to verify compliance with technological regimes, rules of storage and packaging of products between operations.

Output (acceptance) control - quality control of finished products. The purpose of final inspection is to establish compliance of the quality of finished products with the requirements of standards or technical specifications, and to identify possible defects. If all conditions are met, delivery of the product is permitted.

The quality control department also checks the quality of packaging and the correct labeling of finished products.

Input, interoperational and output control can be selective, continuous and statistical.

Selective - control of a part of the product, the results of which apply to the entire batch.

All products are subject to complete control (with untested technological conditions).

Statistical control is preventive. It is carried out throughout the entire technological process in order to prevent defects.

A conditional measure of the quality of goods is their grade.

Variety- this is a qualitative gradation of a product according to one or more indicators established by regulatory documentation.

During acceptance quality control, products are divided into grades, designated by numbers (1, 2, 3, etc.) or words (highest, selected, extra, etc.). Some goods (complex technical goods, furniture, plastic products, etc.) are not divided into grades, but are distinguished as good and bad.

Graduation of goods by grade is carried out according to defectsappearance, less often due to deviations from other properties. All appearance defects are divided into acceptable and unacceptable. Products with unacceptable defects are rejected.

Defects that determine the grade of a product are divided according to the following criteria: origin, size and location, possibility of detection, possibility of correction, degree of significance.

By origin - defects in raw materials, technological defects that arise during storage and transportation.

By size and location - defects are small, large; local, widespread.

If possible, defects are visible (explicit) and hidden.

If possible, corrections include correctable and irreparable defects.

By degree of significance - defects are critical, significant and minor.

If there are critical defects, the use of the goods is impossible or unacceptable.

The degree of reduction in product quality depends on the significance, size, location and number of defects.

Quantity, size and location permissible defects specified in the standards.

Determination of a variety is carried out using a point and restrictive system. The type of product is set to industrial enterprise quality control inspectors. The higher the grade, the higher the quality of the product.

With a point system, each defect or deviation from the nominal value of a property indicator is assessed with a certain number of points, taking into account their significance and size. The grade is determined by the sum of points.

With a restrictive system, a list of acceptable defects, their number, size, and location is established for each grade.

If there is a discrepancy with the standards for a given grade by type, quantity and location of defects, the goods are transferred to a lower grade or defective.

Failure of a product to comply with standards for at least one defect or deviation provides grounds for transferring it to a lower grade or defective.

In a broad sense, quality control is the sum of all measures to ensure a stable level of quality of manufactured products. In a narrow sense this term means a comparison of the actual value of a product with a given value, in which it is established to what extent the products satisfy the requirements established for them.

Quality Control- any planned and systematic activity carried out on manufacturing plant(in a production system), which is implemented to ensure that the goods, services, and processes produced meet the established customer requirements (standards).

In accordance with the ISO 9000:2000 standard, which defines all such standards, quality is a set of certain characteristics and properties of a product or service to satisfy specified needs. This definition turns quality into a value-neutral list of product characteristics (see Diagram 1). It is important that the selected characteristics are measurable and controllable. These may include physical quantities (weight, temperature, density), as well as characteristics relevant to trade (price, quantity per lot, package size) or to customers (for example, positive consideration of wishes). Characteristics can be very different, two main subgroups are qualitative (for example, design) and quantitative (stroke height), each of which can be determined either precisely (for example, the press piston stroke is exactly 150 mm) or have a certain interval (the press piston stroke installed in the range from 20 to 100 mm). In addition, there may be tolerances (150 mm plus or minus 0.1 mm).

Diagram 1. Example of a quality concept for a connecting hose.

Quality control includes both design (design) control and manufacturing inspection, which may differ in the volume of control activities carried out during continuous control and the sample size during selective control. Sampling control (statistical) gives indications about the state of the production process either using statistical methods (production control) or using data obtained about specific gravity defective products in the production batch.

Types of quality control

Thus, a distinction is made between sample, continuous and statistical types. Solid All products undergo inspection; production records are kept of all defects that arise during the manufacturing process of the product.

Selective— control of a part of the product, the inspection results of which apply to the entire batch. This type is precautionary, hence it is carried out throughout the entire production process in order to prevent the occurrence of defects.

Incoming control— checking the quality of raw materials and auxiliary materials entering production. Constant analysis of supplied raw materials and supplies allows us to influence the production of supplier enterprises, achieving improved quality.

Interoperational control covers the entire technological process. This type is sometimes called technological, or current. The purpose of interoperational control is to check compliance with technological regimes, rules of storage and packaging of products between operations.

Output (acceptance) control— quality control of finished products. The purpose of final inspection is to establish compliance of the quality of finished products with the requirements of standards or technical specifications, and to identify possible defects. If all conditions are met, then delivery of the product is permitted. The quality control department also checks the quality of packaging and the correct labeling of finished products.

7 instruments

The following quality control tools are available ( ):

• Summary map of defects;
• Bar chart;
• Quality regulation card;
• Brainstorm;
• Correlation diagram;
• Pareto chart.

Closely related to the technically oriented quality control is the economically oriented approach. Technical specifications should never be considered separately from economic ones. Technological innovation occurs precisely where economists see a good opportunity to reduce costs or great potential to increase profits. The potential for improvement can only be assessed when a clear economic analysis is available together with the technical data. The international standard ISO 9000:2000 defines quality costs as “the costs incurred to ensure the desired quality and convince the consumer that the product will satisfy his needs, as well as losses from insufficient quality.” Diagram 2 gives an idea of ​​how they are divided:

Scheme 2. Structure and classification of quality costs

The cost of a defect is determined by whether it was discovered in production or a consumer complaint. Typical internal costs of marriage are:

• waste, defective products;
• recycling of defects;
• unplanned sorting;
• research of the problem;
• repeated inspections;
• additional time costs due to the need for unforeseen control.

Typical external costs of marriage are:

• costs of replacing defective goods
• maintenance and repair of defective goods
• expenses arising from the provision of a guarantee
• cost of product warranty.

In most cases, it makes sense to divide the costs of defects into the costs of identifying defects, the costs of eliminating defects, and the costs that resulted from defects.

The costs of conformity include the costs necessary to achieve compliance between the planned and existing quality; certification costs include all costs associated with documenting activities. These include costs for certification of quality management systems or costs for software that facilitates the distribution of documents throughout the enterprise. Control costs usually mean the costs of carrying out control activities before the start, during production and control of finished products, as well as the costs of all other quality control tools. This may also include external costs for providing guarantees, obtaining permits, etc. The costs of preventing defects include planning, performance research, supplier assessment, auditing, and staff training. This also includes production maintenance costs.

Practical examples of the use of quality control can be found in Almanac "Production Management"