GOST 19905-74
GOST 19905−74 Hardening of metal products in surface chemical heat treatment. The composition of the General requirements
GOST 19905−74
Group B04
STATE STANDARD OF THE USSR
HARDENING OF METAL PRODUCTS
SURFACE CHEMICAL HEAT TREATMENT
The composition of the General requirements
Strengthening of hardware by surface chemical heat treatment.
Contents of general requirements
Date of introduction 1976−01−01
DEVELOPED by all-Union scientific-research Institute for normalization in mechanical engineering (VNIINMASH)
The Director candidate. tech. Sciences, Verchenko V. R.
The head of the candidate. tech. Sciences, Assoc. Vorobjev V. G.
Performers: Fortuny A. A., Alferova T. K., Rogov A. K.
MADE of all-Union scientific-research Institute for normalization in mechanical engineering (VNIINMASH)
The Director candidate. tech. Sciences, Verchenko V. R.
The draft all-Union scientific-research Institute for normalization in mechanical engineering (VNIINMASH)
Director Of Verchenko V. R.
APPROVED AND promulgated by the Decree of the State Committee of standards of Ministerial Council of the USSR of June 27, 1974, N 1575
REPRINTING. January 1991
This standard specifies the General requirements on technological preparation and implementation of hardening metal products methods of surface chemical heat treatment (carburizing, nitriding, litrovaya, etc.).
1. THE COMPOSITION OF THE GENERAL REQUIREMENTS
1.1. The composition of the General requirements on technological preparation and implementation of hardening metal products methods of surface chemical heat treatment should include:
product requirements designed for chemical-thermal treatment;
requirements for technological processes;
requirements for technical equipment, apparatus and accessories;
requirements the basic technological content;
product requirements, past chemical-heat treatment;
the requirements for control of technological preparation and implementation of surface hardening products;
safety requirements.
1.2. Allowed in branch standards, enterprise standards and other normative technical documentation, depending on the type of production and the nature of the products, technically advanced clarification of the composition of the General requirements.
1.3. The types and completeness of process documents according to GOST 3.1102−81.
1.4. The rules documentation on the processes of heat treatment — according to GOST 3.1405−86.
2. PRODUCT REQUIREMENTS DESIGNED FOR CHEMICAL-THERMAL TREATMENT
2.1. Requirements must regulate the types and limit values of parameters characterizing the material (composition, structure, properties) and to be determined prior to chemical-thermal treatment.
2.2. The requirements should determine the parameters of parts of products (dimensions, roughness of surfaces, etc.) to be checked prior to chemical-thermal treatment:
the amount and allocation of allowances in parts of products, which provides for mechanical treatment after performing the heat treatment with the purpose of giving required shape and size within the required final tolerances, as well as to the local removal of the diffusion layer;
probable during thermal operations of forming parts of products that is not subject to subsequent machining.
2.3. Requirements must regulate the procedure of the unified labeling and control sample.
2.4. Processing of product design for manufacturability — GOST 14.201−73*.
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* Return valid GOST 14.201−83. — Note the CODE.
3. REQUIREMENTS FOR TECHNOLOGICAL PROCESSES
3.1. The requirements to regulate the selection procedure, depending on:
the view of the active (saturated) environment and method of its application;
complex equipment and tooling.
3.2. Requirements must regulate the contents and implementation of the preparatory operations:
training products, including the composition, sequence, contents and methods of operations (the cleaning of surfaces of articles and local protection products from surface hardening);
the preparation of the parties (hatchery) products, including the designation of the lot size (the number of simultaneously loaded products), the conditions of acquisition parties of various products (simultaneous processing).
download products, including the appointment of the ways and means of loading (stacking), the location of products and samples for quality control — mutual and relative to the working bodies (usable space) of the heating unit and snap, the duration and frequency*.
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* If necessary.
3.3. Requirements must regulate the conditions ensure the specified parameters of temperature and time modes, including:
the composition and sequence of related operations of heating, soaking and cooling of the workpieces;
temperature operations;
the duration of the operations;
the temperature on the transitions between adjacent stages (operations) is the rate of heating or cooling, etc.*;
the permissible limit of deviation of process parameters mode.
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* If necessary.
3.4. Requirements must regulate the conditions ensure the specified parameters of the active medium, including:
the nominal composition of constituent materials (chemical products);
the actual composition of the working space for the components selected at the process temperature*;
the permissible limit of deviations in the relative amounts of components or the relationships between their contents;
change the settings on the stages of the process (including cooling after diffusion saturation)*;
modes of excess pressure in the working space*;
the frequency of compliance specified conditions actual;
the locations and methods of sampling environment*.
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* If necessary.
3.5. Requirements must regulate the conditions ensure the specified mechanical effects on the processed products* (for example, hardening in the dies).
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* If necessary.
3.6. Requirements should regulate the content and implementation of the concluding operations, including composition, sequence, modes and methods:
cooling and unloading goods;
additional thermal hardening products*;
edit products*;
cleaning (neutralizing) products*;
removal of local protective coatings*;
prepare products for storage and transportation*;
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* If necessary.
4. THE REQUIREMENTS TO THE TECHNICAL EQUIPMENT, HARDWARE AND TOOLING
4.1. The requirements to regulate the selection procedure, depending on:
the type and mode of the applied chemical and thermal treatment;
the size, shape, weight and brand of material products;
the required parameters of the products;
the desired performance (output);
ensure uniformity and stability of the complex structure and material properties of products after thermochemical processing.
4.2. Requirements should regulate the content and frequency:
full preventive examination of each of the components of the installation, in General, the main types of equipment;
determine the readiness of the unit to work after a long break or repair;
current supervision:
the uniformity of temperature distribution in the working space;
the composition of the gas in the working space;
gas pressure in the working space;
the composition of flue gases;
circulation of the gaseous medium;
tightness;
the composition of the liquid heating baths (molten salt mixture);
the composition of the cooling bath;
circulation of the medium in cooling baths;
mode of mechanical action on the product.
5. REQUIREMENTS THE BASIC TECHNOLOGICAL CONTENT
5.1. The requirements to regulate the selection procedure, depending on:
the type and mode of the applied chemical and thermal treatment;
the size, shape, weight and brand of material products;
the required parameters of the products;
selected technological equipment;
the desired performance (output);
to ensure the homogeneity, the stability of the complex structure and material properties of products after thermochemical processing;
economic parameters.
5.2. Requirements must regulate the ways and peculiarities of the preparation, application and treatment.
5.3. The requirements should determine the parameters to be checked during the application process, and the frequency of their inspections.
5.4. Requirements must regulate the rate of flow.
6. PRODUCT REQUIREMENTS, PAST CHEMICAL-HEAT TREATMENT
6.1. The requirements should determine the quality indicators of hardening of the surface diffusion layer and core products:
the geometric parameters of the surface diffusion layer (ratio of layer and core*);
the chemical composition of the surface of the diffusion layer;
the mechanical properties (including hardness) of the material surface of the diffusion layer and core, controlled after thermochemical hardening;
structural factors of the material in the surface diffusion layer and in the core, controlled after thermochemical hardening;
physical properties or other parameters of the surface diffusion layer and the core;
the appearance of the surfaces of products, including valid local defects and color, are monitored* when chemical-thermal treatment is the final operation.
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* If necessary.
6.2. Requirements must regulate the limit values of controlled parameters.
Note. Specifies the desired character of the distribution of controlled parameters on the thickness of the diffusion layer and the surface of the product*.
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* If necessary.
6.3. Requirements must regulate the permissible distortion (deformation) of the workpiece during chemical heat treatment;
basic geometrical parameters (as well as the roughness of the surface) to be controlled after the operation of hardening;
marginal changes in the values of monitored geometric parameters of products after thermochemical hardening compared with the values of the relevant parameters before hardening.
7. THE REQUIREMENTS FOR CONTROL OF TECHNOLOGICAL PREPARATION AND IMPLEMENTATION OF SURFACE HARDENING OF PRODUCTS
7.1. Requirements must regulate methods:
the input control of geometrical parameters, material quality in accordance with the requirements of sec. 2;
control operation modes of the selected technological process of chemical-thermal treatment of products in accordance with the requirements of sec. 3;
operational and periodic monitoring of the status of the working characteristics and parameters of technological equipment, instruments and equipment in accordance with sec. 4;
input, operational and periodic monitoring of the chemical composition and technological properties of the basic materials in accordance with the requirements of sec. 5;
the preparation and use of voucher specimens (including shape and dimensions, selection of material, manufacture, number of samples, ensuring the identity of the structure and properties of the material of the workpieces and samples, methods for evaluating results, etc.);
quality control of surface hardening of products of control samples, toughened products in accordance with the requirements of sec. 6.
Note. Category control (continuous, sampling, float, etc.) and control parameters are set depending on the type, purpose and conditions of operation of products.
8. SAFETY REQUIREMENTS
8.1. For hardening of products of chemical-heat treatment must be performed following safety requirements:
safety requirements for design and operation of process heating and mechanical devices;
safety requirements for technological application of gas, solid (granular) and liquid substances with hazardous properties;
electrical safety requirements for the applicable equipment and tooling;
requirements of fire and explosion (alarm, extinguishing agents, etc.);
requirements for ensuring normal sanitary and hygienic conditions in the premises and workplaces of chemical-heat treatment (air quality, temperature, noise, illuminance, etc. in the working area);
ergonomic requirements to ensure optimal operating conditions of the respective production areas;
requirements for mechanization of works connected with lifting and moving heavy loads;
requirements for the application of collective and individual protection;
requirements for personnel permitted to participate in the processes of chemical-heat treatment (selection of personnel, training, medical examination, etc.);
requirements for methods, tools and procedure for safety monitoring.
8.2. For hardening of products of chemical-heat treatment shall be performed in the security requirements for the prevention of environmental pollution production of waste (collection and neutralization or the necessary dilution of gaseous, liquid and solid, including dust waste their removal in accordance with the rules of the State sanitary supervision).
The text of the document is verified by:
the official publication of the
M.: Publishing house of standards, 1991
