GOST 20495-75
GOST 20495−75 Hardening metal parts surface chemical heat treatment. Characteristics and properties of the diffusion layer. Terms and definitions
GOST 20495−75
Group B00
STATE STANDARD OF THE USSR
HARDENING OF METAL PARTS SURFACE
CHEMICAL-HEAT TREATMENT.
CHARACTERISTICS AND PROPERTIES OF THE DIFFUSION LAYER
Terms and definitions
Case-hardening of metal components.
Diffusion layer characteristics and properties. Terms and definitions
Date of introduction 1976−01−01
Promulgated by Decree of the State Committee of standards of the USSR Council of Ministers dated 12 February 1975 No. 407
REPRINTING. January 1995
This standard sets used in science, engineering and manufacturing of terms and definitions of basic concepts in the field of characteristics and properties of diffusion layers formed during the hardening of metal parts surface chemical heat treatment.
The terms laid out in this standard are mandatory for use in all types of documentation, manuals, tutorials, technical and reference literature.
For each concept has a single standardized term. The use of terms — synonyms of the normalized term is prohibited. Unacceptable for use synonymous terms given in the standard as a reference and is marked with the note «NDP».
For certain of the standardized terms in standard given their short forms that may be used in cases precluding the possibility of their different interpretation.
In the standard as reference is given to foreign equivalents in German (D) English (E) languages for most of the standardized terms established by this standard.
Standardized terms in bold, short form — light, invalid synonyms in italics.
The standard lists the indexes contained in this term in Russian, and equivalents in English and German.
| The term |
Definition | ||
| GENERAL CONCEPTS | |||
| D. Allgemeine Begriffe E. General notions | |||
1. Surface saturation |
The surface of the part, or part on which the chemical-thermal treatment the material interacts with the surrounding active medium | ||
| 2. The diffusion layer D. Diffusionsschicht E. Diffusion layer; case |
Layer component material at the surface of saturation, different from the original chemical composition as a result of chemical-heat treatment. Note. The change in chemical composition causes changes in the structure and properties of the diffusion layer | ||
| 3. Core D. Grundmetall E. Core |
The material of the part under the diffusion layer is not affected by the influence of the surrounding active medium | ||
| 4. Area of the diffusion layer Zone layer D. Diffusionsschichtzone E. Diffusion layer zone |
Part of the diffusion layer, having the same signs different from the signs of adjacent parts, limited by imaginary surfaces, each of which is generally equidistant from the surface of saturation. Note. One of the boundary surfaces coincide with the surface of saturation | ||
5. Structural zone of the diffusion layer |
Area of the diffusion layer, which material possesses the same structural characteristics. | ||
| 6. The outer zone of the diffusion layer The outer zone D. Diffusionsschichtrandzone E. Diffusion layer outer zone |
Area of the diffusion layer, located directly under the surface saturation (Fig.1) | ||
| 7. Dimensional plot of diffusion layer Dimensional plot layer D. Messbereich der Diffusionsschicht E. Diffusion layer measuring portion |
Part of the diffusion layer to determine its characteristics and conditionally restricted arbitrarily chosen surfaces, each of which is equidistant from the surface of saturation | ||
8. The transitional area diffusion layer |
Adjacent to the core is the inner part of the diffusion layer, the length of which is determined by the difference between total and effective thickness (see terms of PP.12, 13 and shit.2) | ||
9. Slicing method of determining the quality of the diffusion layer |
Research method the diffusion layer, consisting in the sequential (from the surface to the core) the definition of the transverse cone of the characteristics of relatively small thickness or removing and analysing the appropriate volumes of material and (or) the study of newly formed surfaces (Fig.3) | ||
THE CHARACTERISTICS OF THE DIFFUSION LAYER | |||
| D. Parameter der Diffusionsschicht E. Diffusion layer parameters | |||
| 10. The basic parameter of the diffusion layer Basic parameter D. Basischer Parameter der Diffusionsschicht E. Diffusion layer basic parameter |
The material parameter that serves as in this test the criterion for judgment about quality change in the distance function of the surface saturation. Note. As the base parameter can be the concentration of a specific component chemical composition, property or a structural characteristic | ||
| 11. The nominal value of the underlying parameter of the diffusion layer The nominal value of the underlying option D. des Nominalwert der basischen Parameters Diffusionsschicht E. Diffusion layer basic parameter nominal value |
The value of the base parameter of the diffusion layer, averaged over the measuring area. Note. The thickness of the measuring area is set depending on the testing purpose, method and means of measuring a baseline parameter (Fig.4) | ||
| 12. The total thickness of the diffusion layer The total thickness of the layer NDP. The depth of the diffusion layer D. Gesamttiefe der Diffusionsschicht E. Diffusion layer full thickness |
The shortest distance from the surface of saturation to the core, as defined by a prescribed method on the value of the underlying parameter. Note. Allowed the use of the word «depth» combined with the name of the process. For example: the depth of cementation, depth of nitriding, the depth of diffusion of chromium plating, etc. | ||
| 13. The effective thickness of the diffusion layer The effective thickness of the layer D. Effektivetiefe der Diffusionsschicht E. effective Diffusion layer thickness; effective case depth |
Of the total thickness of the diffusion layer, defined by the shortest distance from the surface of saturation to the measuring station, characterized by installed limit the nominal value of the underlying parameter (see the devil.2) | ||
| 14. The thickness of the zone (measuring area) of the diffusion layer The thickness of the zone (measuring section) D. Dicke der Diffusionsschichtzone E. Diffusion layer zone thickness |
The shortest distance between the conditional boundary surface area (measuring area), see hell.1 | ||
| 15. The depth of the area (measuring area) of the diffusion layer The depth of the zone (measuring section) D. Lagetiefe der Diffusionsschichtzone E. Diffusion layer zone depth of bedding |
The shortest distance from the surface of saturation to the nearest boundary surface area (measuring area) of the diffusion layer (see the devil.1) | ||
| 16. The distribution of the underlying parameter of the diffusion layer The distribution of the underlying parameter D. Verteilung des Parameters der basischen Diffusionsschicht E. Diffusion layer basic parameter distribution |
Pattern changes in the values of the underlying parameter along the normal to the surface of saturation | ||
| 17. The composition of the outer zones of the diffusion layer D. Zusammensetzung der Diffusionsschichtrandzone E. Diffusion layer outer zone content |
The average content of the considered components of the composition in the area from the surface of saturation: a) at the harshness of the distribution to speed of concentration changes corresponding to the phase boundary; b) with a smooth change in the concentration to the preset nominal values of the basic parameter | ||
PROPERTIES OF THE DIFFUSION LAYER________________ In terms of the properties of the diffusion layer, not shown in this section (for example, abrasion resistance, resistance to adhesion, heat resistance, etc.) are applied in the normal values established by the relevant normative documents. | |||
| D. Beschaffenheiten der Diffusionsschicht E. Diffusion layer properties | |||
18. The surface hardness of the diffusion layer |
The hardness, measured with the established method on the surface of saturation | ||
19. The hardness of the outer zones of the diffusion layer |
The surface hardness measured by the method in which the measurement result depends only on properties of the external zone of the diffusion layer and not depend on the properties of the rest of the company. | ||
20. Surface the fragility of the diffusion layer |
The ability of the diffusion layer to brittle fracture under a local load estimate method | ||
21. The hardenability of the diffusion layer |
Property component material within the diffusion layer, characterized by the distribution of hardness as the base parameter | ||
22. The hardenability of the diffusion layer |
Property component material within the diffusion layer, characterized by the highest surface hardness, which he can acquire after quenching under optimal conditions. Note. In certain types of processing the highest value of hardness can be achieved at a certain depth under the surface of saturation | ||
23. The uniformity of the surface of saturation |
The surface condition of saturation, characterized by at any point consistently selected limit values of determined parameters | ||
| 24. The uniformity of the diffusion layer The homogeneity of the layer D. Gleichartigkeit der Diffusionsschicht |
As the diffusion layer, characterized by the constancy of the distribution of the underlying parameters under any point of surface saturation | ||
| 25. The continuity of the external zone of the diffusion layer The continuity of the external zone D. Ununterbrochenheit der Diffusionsschichtrandzone E. Diffusion layer outer zone continuity |
The uniformity of the diffusion layer in the parameters characterizing the external zone | ||
| 26. Configuration the effect of the projection The effect of the projection D. Gestaltungseffekt der Vorsprungsteiles E. Configurational effect of protrude part |
The formation of local thickening of the diffusion layer as a result of flow of the diffusing substance at the same time from different sides of the protruding part, which may be accompanied by a local excess of its average concentration (Fig.5) | ||
| 27. Configuration effect depression The effect of the depression D. Gestaltungseffekt der Vertiefung E. Configurational effect of deep hollow |
Education local thinning of the diffusion layer due to insufficient supply of diffusing substance from the surface of saturation in the cavity part, which may be accompanied by local decrease of its average concentration (see the devil.5) | ||
der Diffusionsschicht
der Diffusionsschicht
der Diffusionsschicht
der Diffusionsschicht
der Diffusionsschicht
der Diffusionsschicht
der Diffusionsschicht
der Diffusionsschicht
— thickness area (measuring area) of the diffusion layer;
the depth of the zone (measuring section)
diffusion layer; V. H. — the outer zone of the diffusion layer.
Damn.1
PZ is a transitional area diffusion layer; With the core; — the total thickness of the diffusion layer;
— the effective thickness of the diffusion layer;
— the value of the underlying parameter at the surface;
is the limit value of basic parameter set for the effective thicknesses;
— the value of the base parameter of the core.
Damn.2
1, 2, 3,… (-1),
— numbers of plots of the diffusion layer sequentially removed
and studied composition; 1', 2', 3' … (-1)',
the numbers of surface plots of the diffusion layer,
consistently investigated the structure and properties.
Damn.3
— the nominal value of the underlying parameter (for dimensional plot of thickness
).
Damn.4
And configuration the effect of the projection; B — configuration the effect of the depression; — the total thickness of the diffusion layer
Damn.5
ALPHABETICAL INDEX OF TERMS
| Analysis stratified |
9 |
| The depth of the diffusion layer |
12 |
| The depth of the zone (measuring section) |
15 |
| The depth of the area (measuring area) of the diffusion layer |
15 |
| The hardenability of the diffusion layer |
22 |
| The value of the base parameter of the diffusion layer nominal |
11 |
| The value of the underlying parameter nominal |
11 |
| Area external |
6 |
| Area of the diffusion layer |
4 |
| Area of the diffusion layer external |
6 |
| Area of the diffusion layer transition |
8 |
| Area of the diffusion layer of the structural |
5 |
| Area transition |
8 |
| Zone layer |
4 |
| Area structural |
5 |
| Slicing method of determining the quality of the diffusion layer |
9 |
| The uniformity of the diffusion layer |
24 |
| The uniformity of the surface of saturation |
23 |
| The homogeneity of the layer |
24 |
| The basic option |
10 |
| Parameter diffusion layer base |
10 |
| Surface diffusion |
1 |
| Surface saturation |
1 |
| The surface reaction |
1 |
| The hardenability of the diffusion layer |
21 |
| The distribution of the underlying parameter |
16 |
| The distribution of the underlying parameter of the diffusion layer |
16 |
| Core |
3 |
| The diffusion layer |
2 |
| The composition of the outer zones of the diffusion layer |
17 |
| The continuity of the external zone |
25 |
| The continuity of the external zone of the diffusion layer |
25 |
| The hardness of the outer zones |
19 |
| The hardness of the outer zones of the diffusion layer |
19 |
| The hardness of the diffusion layer surface |
18 |
| The hardness of the surface |
18 |
| The thickness of the diffusion layer common |
12 |
| The thickness of the diffusion layer effective |
13 |
| The thickness of the zone (measuring section) |
14 |
| The thickness of the zone (measuring area) of the diffusion layer |
14 |
| The thickness of the layer of common |
12 |
| The layer thickness is effective |
13 |
| A plot of diffusion layer dimensional |
7 |
| The portion of the layer dimensional |
7 |
| The fragility of the diffusion layer surface |
20 |
| The effect of the depression |
27 |
| The effect of trench configuration |
27 |
| The effect of the projection |
26 |
| The effect of the ledge configuration |
26 |
ALPHABETIC INDEX OF EQUIVALENTS TERMS IN GERMAN LANGUAGE
|
22 |
| Basischer Parameter der Diffusionsschicht |
10 |
| Dicke der Diffusionsschichtzone |
14 |
| Diffusionsschicht |
2 |
| Diffusionsschichttrandzone |
6 |
| Effektivetiefe der Diffusionsschicht |
13 |
|
21 |
|
5 |
| Gesamttiefe der Diffusionsschicht |
12 |
| Gestalfungseffekt der Vertiefung |
27 |
| Gestaltungseffekt der Vorsprungsteiles |
26 |
| Gleichartigkeit der Diffusionsschicht |
24 |
Gleichartigkeit der |
23 |
| Grundmetall |
3 |
| Lagetiefe der Diffusionsschichtzone |
15 |
| Messbereich der Diffusionsschicht |
7 |
| Des Nominalwert der basischen Parameters Diffusionsschicht |
11 |
|
18 |
|
20 |
|
19 |
| 1 | |
|
8 |
| Ununterbrochenheit der Diffusionsschichttrandzone |
25 |
Verfahren | |
| Diffusionsschicht |
9 |
| Verteilung des Parameters der basischen Diffusionsschicht |
16 |
| Zuzammensetzung der Diffusionsschichttrandzone |
17 |
der Diffusionsschicht
der Diffusionsschicht
der Diffusionsschicht
der Diffusionsschicht
der Diffusionsschicht
der Diffusionsschicht
der Diffusionsschicht
derALPHABETICAL INDEX OF THE TERMS IN ENGLISH
| Case |
2 |
| Configurational effect of deep hollow |
27 |
| Configurational effect of protrude part |
26 |
| Core |
3 |
| Diffusion layer |
2 |
| Diffusion layer basic parameter |
10 |
| Diffusion layer basic parameter distribution |
16 |
| Diffusion layer basic parameter nominal value |
11 |
| Effective Diffusion layer thickness |
13 |
| Full Diffusion layer thickness |
12 |
| Diffusion layer hardenability |
21 |
| Diffusion layer measuring portion |
7 |
| Diffusion layer outer zone |
6 |
| Diffusion layer outer zone content |
17 |
| Diffusion layer outer zone continuity |
25 |
| Diffusion layer outer zone hardness |
19 |
| Diffusion layer structural zone |
5 |
| Diffusion surface layer brittleness |
20 |
| Diffusion layer surface hardness |
18 |
The text of the document is verified by:
the official publication of the
M.: Publishing house of standards, 1995
