GOST 21022-75
GOST 21022−75 chromic Steel for precise bearings. Specifications (with Amendments No. 1, 2, 3, 4)
GOST 21022−75*
Group В32
INTERSTATE STANDARD
CHROMIC STEEL FOR PRECISE BEARINGS
Specifications
Chromic steel for precise bearinqs. Specifications
OKP 09 5600
Date of introduction 1977−01−01
The decision of the State standards Committee of the Council of Ministers of the USSR dated 25 July 1975 N 1928 date of introduction is established with 01.01.77
The expiration time limit is removed by the Resolution of Gosstandart from
* Publishing (October 2000) with Amendments No. 1, 2, 3, 4, approved in November 1977, September 1981, July 1986, July 1991 (IUS 1−78, 12−81, 10−86, 10−91)
This standard applies to hot rolled and forged steel with a diameter of 120 mm, and calibrated with a diameter of 40 mm, grade SHKH15-SHD obtained by remelting in vacuum-arc furnace electrode of steel grade SHKH15, made of metal of electroslag remelting.
Steel intended for the manufacture of precision bearings.
1. ASSORTMENT
1.1. Steel shall be manufactured in the bars section:
— HR — up to 120 mm;
— forged over 80 to 120 mm;
— calibrated to 40 mm.
1.2. In form, the cross-sectional size, limit deviations and other requirements to the assortment steel shall conform to the following standards:
— hot rolled diameter up to 120 mm GOST 2590−88;
— forged larger than 80 to 120 mm GOST 1133−71;
— grooved with a diameter of 40 mm GOST 7417−75 and Annex 1 to the present standard.
Note. Hot rolled steel with a diameter of 120 mm is made with plus extreme deviations corresponding to the specified table.2 GOST 2590−88. By agreement with the consumer steel can be manufactured with bilateral limit deviations specified in table.1 GOST 2590−88.
1.3. Steel shall be manufactured of the following length:
— hot rolled with a diameter of 80 mm and 2.8−4.0 m;
— hot rolled and forged a diameter of over 80 to 120 mm 2.0−4.0 m;
— grooved with a diameter of 40 mm and 3.0−4.5 m.
(Changed edition, Rev. N 3).
1.4. The local curvature of the hot rolled steel should not exceed 4 mm per 1 m length, forged and calibrated — no more than the rules stipulated in the relevant standards assortment.
1.5. The ends of the rods should be trimmed evenly. At the ends of bars should be free of burrs and significant collapse. The ends of the rods are calibrated and hot rolled steel with diameter up to 50 mm inclusive, must be trimmed or broken off.
The ends of the grooved steel should not be bent.
Autogenous cutting is not allowed.
1.6. Hot rolled and calibrated steel with a diameter of 16 mm, in agreement with the consumer can be supplied in coils.
Hot rolled steel in coils are supplied without trimming the ends.
1.5, 1.6. (Changed edition, Rev. N 3).
2. TECHNICAL REQUIREMENTS
2.1. The chemical composition of steel grade SHKH15-stepper motor must comply with the brand SHKH15 according to GOST 801−78; wherein the mass fraction of sulfur should not exceed 0,010% and phosphorus of 0.025%.
Note. In the designation of the stamps letters and numbers mean:
Sh — bearing;
X — chromium alloy;
15 — average content (1,5%) of chromium in steel;
Stepper motors — vacuum arc remelting of steel electroslag remelting.
(Changed edition, Rev. N 1).
2.2. Steel with a diameter of 80 mm made of annealed, diameter more than 80 mm — annealed or without annealing.
2.3. (Deleted, Rev. N 1).
2.4. On the surface of hot-rolled and forged bars should not be wooloowin, flaws, prisoner of laps, cracks, and rolled out the crust.
Allowed some risks, prints, rabiza, as well as traces of Stripping, if their depth does not exceed half the diameter tolerance, measured from the nominal.
2.5. The surface of the grooved bars must be clean, smooth, without cracks, wooloowin, pinches, scratches, captivity, Slavin and scale. On the surface of the grooved bars intended for the manufacture of parts by milling, allowed individual risks (rabiza, wrinkles) to a depth of not more than 1% of the diameter of the rod.
Calibrated rods can be produced with a polished surface according to GOST 14955−77.
(Changed edition, Rev. N 4).
2.6. Steel intended for forging and stamping, must withstand tests on sediment: hot rolled untreated steel up to 60 mm inclusive, the hot upset; calibrated sizes up to 30 mm inclusive, on a cold draught.
In upset samples should be free of tears and cracks from the drop-down defects.
(Changed edition, Rev. N 1).
2.7. Annealed hot rolled and calibrated steel should have a hardness 179−207 HB (indentation diameter of 4.5 to 4.2 mm).
2.8. Macrostructure of steel shall not have shrinkage, looseness, blistering, delamination, cracks, inclusions, burned, pacenow and other foreign inclusions that are visible without using the magnifying devices.
Allowed the Central porosity, point heterogeneity and phase separation in the square in accordance with the requirements of table.2.
Table 2*
| Diameter of bars, mm |
Allowable defects in points, not more | |||
| Central porosity |
Point heterogeneity |
Exudation square |
Layer-by-layer crystallization and light contour | |
| Up to 60 incl. |
0,5 |
0,5 |
0,5 |
By agreement with the consumer |
| SV. 60 to 80 incl. |
0,5 |
1,0 |
0,5 |
|
| «80» 120" |
1,0 |
1,0 |
1,0 |
|
________________
* Table.1. (Deleted, Rev. N 1).
2.9. The structure of the fracture across the grain of the annealed hot-rolled and calibrated steel structure and longitudinal fracture in quenched samples annealed hot-rolled and calibrated steel needs to be uniform, fine, no burnout, shrinkage, and for the samples in the hardened state, and porcelain-like.
2.10. Obesplozhennym layer (ferrite + transition zone) in bars hot rolled and forged steel shall not exceed per side:
| 0.20 mm |
— with a diameter of from | 4 to 10 mm incl. |
||||
| 0.25 mm |
« | « | St. |
10 to 15 mm" | ||
| 0.30 mm |
« | « | « |
15 to 30 mm" | ||
| 0.40 mm |
« | « | « |
30 to 50 mm" | ||
| 0.60 mm |
« | « | « |
50 to 70 mm" | ||
| 0.85 mm |
« | « | « |
70 to 100 mm" | ||
| 1,10 mm |
« | « | « |
100 to 120 mm" | ||
2.11. Obesplozhennym layer in the grooved steel rods shall not exceed 1% of diameter.
2.12. The microstructure of annealed steel with a diameter of 80 mm shall consist of uniformly distributed fine pearlite, corresponding to points 1−4 scale N 8 GOST 801−78.
The microstructure of the untreated steel, and annealed steel with a diameter of more than 80 mm is not standardized.
(Changed edition, Rev. N 3).
2.13. Pollution steel non-metallic inclusions, which are evaluated at points of the attached timeline (Annex 2), must not exceed the limits specified in table.3.
Table 3
| Diameter of bars, mm |
Oxides |
Sulfides |
Silicates |
Globular inclusions |
Point inclusion |
| Points, no more than | |||||
| Up to 25 |
1 |
2 |
1 |
2 |
2 |
| SV. 25 to 50 |
2 |
3 |
3 |
3 |
2 |
Notes:
1. Allowed attack (score more than the specified in table.3) for 10% of the samples for the two types of inclusions; the attack must not exceed 1 point in excess of established standards.
2. Nitrides stroke is graded on a scale of oxides, and scattered single — point scales, and globular inclusions.
(Changed edition, Rev. N 1).
2.14. For the assessment of pollution steel non-metallic inclusions may be used a method of counting the number of inclusions according to GOST 1778−70. The permissible limits of contamination of steel inclusions are established by agreement with the customer on data accumulation.
2.15. Microporosity in steel is not allowed.
2.16. Structural banding, carbide liquation and carbide mesh bars with a diameter of 80 mm must not exceed the limits specified in table.4.
Table 4
| Diameter of bars, mm |
Structural banding |
Carbide liquation |
Carbide mesh |
| Points, no more than | |||
| Up to 30 |
1,5 |
1 |
3 |
| SV. 30 to 50 |
2 |
1 |
3 |
| «50» 80 |
3 |
2 |
3 |
2.17. By order of the consumer steel of diameter greater than 28 mm comes with a control hardenability. Hardness norms characterizing the hardenability, are determined by the agreement of the consumer and the manufacturer.
3. ACCEPTANCE RULES
3.1. Steel present to the acceptance of the parties. The party must consist of bars of one melting vacuum-arc remelting, of the same diameter and the mode of heat treatment. To vacuum arc melting ingots are smelted from a single source electrodes melting of electroslag remelting.
3.2. To check the quality of steel is taken:
a) one sample from melting for chemical analysis;
b) 10% of the bars from the party — size and curvature of bars; all the bars — to check the quality of a surface;
C) one to three bars from a 1 ton, but not less than five to ten bars from the party of bars with thickness up to 30 mm and 10% of the bars from the party of bars with thickness more than 30 mm — to check the hardness of the annealed steel;
g) three bars from the party on hot and cold draught;
d) the two bars larger than 30 mm from the bottoms to check the macrostructure;
e) 10% of bars from melting calibrated and hot rolled steel with a diameter of 40 mm and two rods from melting of hot rolled steel with a diameter of over 40 mm — to check the structure of fracture across the grain of the metal.
Note. At 100% ultrasonic testing of bars to check the structure of fracture take two rods from melting.
g) two bars from the party of steel with a diameter of over 45 mm — to check the structure of fracture for the quenched samples along the fiber;
h) five bars from the party — to check the microstructure and three to five bars to test the hardness — when checking the depth bezoperatsionnogo layer;
and) ten bars from the bottoms to check pollution steel non-metallic inclusions;
K) six bars from the party hot-rolled or forged steel, or ten rods from melting for steel calibrated — to check the microporosity;
l) five bars from the party — to verify structural poloschatosti; six bars carbide liquation and five bars carbide mesh;
m) all the bars of the party — to verify compliance of steel grades;
n) one two bar men to control hardenability.
(Changed edition, Rev. N 4).
3.3. In case of discrepancy between the results of any test (except for tests on non-metallic inclusions) the requirements of this standard re tests carried out in accordance with the requirements of GOST 7566−94.
If unsatisfactory test results of steel on nonmetallic inclusions, a second control on ten samples taken from the other bars in the party — (melting) in the method of rating scales and six samples in the method of counting inclusions.
If there is an attack by one species of inclusions, the melting does not meet the requirements of this standard. The results of repeated control are final.
Melting with the primary test attacks exceeding the norms table.3 three points, the re are not subject to control, and results of primary control are final.
4. TEST METHODS
4.1. Sampling to determine the chemical composition of the steel is carried out according to GOST 7565−81, chemical analysis according to GOST 12344−88*, GOST 12345−88**, GOST 12346−78, 12347−77 GOST, GOST 12348−78, 12350−78 GOST, GOST 12352−81, 12355−78 GOST, GOST 12356−81, 12357−84 GOST, GOST 28473−90 or other methods providing the required accuracy.
_________________
* On the territory of the Russian Federation GOST 12344−2003.
** On the territory of the Russian Federation GOST 12345−2001. — Note the CODE.
In case of dispute between consumer and manufacturer chemical composition of steel is determined according to the specified standards.
The method of determining the content of titanium and aluminum in steel, defined by the requirement of the consumer is established by agreement with the consumer.
(Changed edition, Rev. N 2).
4.2. To check the quality of steel is taken one sample from a rod in accordance with the requirements of section 3.2 (subparagraphs C, d, d, e, f, h, I, K, l, m, n) and n.3.3.
4.3. Compliance grade of steel test method of arcing, stethoscopes or other nondestructive method.
4.4. Hardness on the Brinell hardness test according to GOST 9012−59 after Stripping bezoperatsionnogo layer at both ends of the selected rods. Allowed to check the hardness in the cross section of the samples.
Note. If unsatisfactory results of the repeat test is performed on the ends of the rods after cleaning bezoperatsionnogo layer.
The number of prints at each end must be at least two. Each value of hardness shall be those specified in p.2.7.
(Changed edition, Rev. N 3).
4.5. The surface of the bars is controlled with the use of non-destructive methods or by visual inspection without the use of magnifying devices. Hot rolled and forged bars by visual inspection should be clarified or snake rings with a pitch of 200−500 mm.
When checking the user is allowed to lighten the bars snake in increments of 100 mm.
4.6. Test on a cold draught at height and hot sediment at
height conducted by the method GOST 8817−82. When hot the sediment samples are heated to the forging temperature.
4.7. Macrostructure of steel is controlled according to GOST 10243−75. Macrostructure of steel with a diameter of over 30 mm check of the etched cross templete and fracture. Bars with a diameter of 30 mm and less only check for a break.
Note. By agreement with consumer it is permitted to use non-destructive methods of control of the macrostructure.
4.8. (Deleted, Rev. N 1).
4.9. Bezoperatsionnogo the depth of the layer is determined by the method of T. E. D. S. or method M according to GOST 1763−68.
On a calibrated rods with a diameter of 30 mm and the presence of bezoperatsionnogo layer can be determined by T according to GOST 1763−68.
The hardness of the steel in the control by this method after cleaning of the surface to a depth corresponding to the norms of the decarburization specified in paras.2.10 and 2.11, should not be below 62 HRC(HRC 61).
(Changed edition, Rev. N 1, 3).
4.10. The microstructure of the steel is checked on the micro-sections with a transverse direction of the fiber.
Samples cut in the form of washers with a thickness of 10−25 mm.
From cut micro-sections of samples made. When the diameter of bars up to 40 mm is recommended to make the micro-sections across the cross section, more than 40 mm — cut out quarter circle.
The micro-sections etched to reveal the microstructure in a 2−4% solution of nitric acid in ethyl alcohol according to GOST 17299−78 or other reagent.
Evaluation of the microstructure of pearlite is produced by visual comparison with standard scale N 8 GOST 801−78 with increasing 450−600.
(Changed edition, Rev. N 3).
4.11. Clipping samples and manufacturing of micro-sections for the assessment of nonmetallic inclusions and microporosity is produced in accordance with the requirements of GOST 1778−70. The mode of heat treatment of samples should be: quenched (845±10) °C, cooling in oil, leave 150−170 °C for 1 h.
The rating of nonmetallic inclusions in as much as the scores are produced under a microscope at magnification of 90−110, and the diameter of the field of view of 1.1−1.3 mm by comparing the most polluted places of the microsection with fotoatteli the attached scale.
A score of «0» is placed in the absence of any kind of inclusions, and also when the inclusions is two times less compared to score 1.
At simultaneous presence in the same field of view several types of inclusions appreciate each of the inclusions individually.
4.12. Counting the number of non-metallic inclusions are produced according to GOST 1778−70 method K1 in the area of 12 cm(2 cm
on each microsection).
4.13. Assessment of the microporosity produced by the method and scales GOST 801−78.
4.14. Structural banding evaluated on the longitudinal sections at a scale N 5 according to GOST 801−78.
Clipping, thermal processing of samples and manufacturing of micro-sections are produced as specified in claim 4.11.
Samples taken from the untreated steel, subjected to pre-annealing on hardness (see p.2.7).
The micro-sections etched in freshly prepared 4% alcohol solution of nitric acid, the etching time of 15−20 C.
The evaluation of structural poloschatosti produced by increasing 90−110by comparison with a standard of N scale 5 GOST 801−78.
On each thin section to assess the maximum structural banding. If the evaluation of structural poloschatosti cannot be conducted by one of the two neighboring points, it is allowed to estimate intermediate points 0,5; 1,5; 2,5 etc.
For test result take the maximum score from the evaluations of the samples.
4.15. Carbide liquation and carbide mesh is evaluated by scales N 6 and N 4 according to GOST 801−78.
Clipping samples, heat treatment and manufacture of thin sections for evaluation of carbide liquation and carbide of mesh produced as described in section 4.11. Thin section etched in 4% alcohol solution of nitric acid until blackening and distinct identification of grains of carbides.
Carbide liquation appreciate if you increase 80−110comparison with standard N scale 6 GOST 801−78. The remains of a carbide mesh estimate with increasing 450−500
comparison with a standard of N scale 4 GOST 801−78. For bars with a diameter of 61 to 80 mm Central zone with a diameter of 25 mm carbide on the net not in control.
Sections on carbide liquation and carbide mesh evaluated according to the worst place on the cone. Party metal is evaluated by the maximum score estimates of the samples.
4.14,4.15. (Changed edition, Rev. N 3).
4.16. Allowed to assess the structural banding, carbide liquation and carbide mesh on the samples for the control of nonmetallic inclusions.
4.17. If there are differences in the microstructure, nonmetallic inclusions, structural banding, carbide liquation and carbide mesh evaluated when the corresponding diameter of the field of view and poliatlonu.
4.18. Hardenability of steel is controlled according to GOST 5657−69.
The heating temperature for hardening of the samples must be 845−855 °C. the heating Time of the sample to the quenching temperature should be 30−50 min. Exposure sample at a temperature of quenching after heating should be 30 min. by agreement with the consumer, the heating time and holding time can be specified.
The measurement of hardness is produced at a distance of 1,5; 3,0; 4,5; 6,0; 7,5; 9,0 mm from the end.
5. MARKING, PACKAGING, TRANSPORTATION AND STORAGE
5.1. Labeling, packaging — according to GOST 7566−94 with the following additions.
5.1.1. All bars with a diameter or thickness from 30 to 70 mm inclusive should be a stigma on the end, and rods of diameter or thickness over 70 mm at the end. Allowed on rods of diameter or thickness from 30 to 70 mm stamp to put on the end.
5.1.2. For bars with diameter or thickness less than 30 mm, the emboss stamp to append to each bundle label.
5.1.3. Calibrated steel for protection against corrosion should be covered with easily removed grease. According to customer requirements, calibrated steel delivered without lubrication.
5.1.4. Calibrated steel at the customer’s request supply of synthetic foil or paper box packing.
(Changed edition, Rev. N 2).
5.2. Transportation of produce according to GOST 7566−94.
5.3. The products should be stored in closed warehouses.
5.2, 5.3. (Added, Rev. N 3).
APPENDIX 1. ADDITIONAL SIZES OF GROOVED BEARING STEEL
ANNEX 1
The diameters of rods, mm: 5,4; 5,7; 6,2; 6,6; 7,2; 7,6; 7,9; 8,1; 8,3; 8,4; 8,6; 8,7; 9,1; 9,3; 9,4; 9,6; 9,7; 10,1; 10,3; 10,4; 10,7; 10,9; 11,3; 11,4; 11,6; 11,7; 11,9; 12,1; 12,3; 12,4; 12,6; 12,7; 12,9; 13,3; 13,4; 13,6; 13,8; 14,1; 14,2; 14,3; 14,4; 14,6; 14,7; 14,8; 14,9; 15,2; 15,4; 15,8; 16,3; 16,6; 16,7; 16,8; 17,2; 17,3; 17,4; 17,6; 17,8; 17,9; 18,2; 18,3; 18,4; 18,8; 19,1; 19,2; 19,3; 19,8; 20,2; 20,4; 20,6; 20,8; 21,4; 21,6; 21,7; 21,8; 22,5; 22,8; 22,9; 23,2; 23,5; 23,8; 24,2; 24,5; 24,8; 25,5; 26,2; 27,5; 28,5.
Note. Limit deviations for calibrated soft steel of the dimensions mentioned above must comply with the requirements of GOST 7417−75 to the nearest rod size.
APPENDIX 2.
ANNEX 2
Scale N 1. OXIDES
Scale N 1
OXIDES
Score 1
Score 2
Score 3
Score 4
Scale N 2. SULFIDES
N Scale 2
SULFIDES
Score 1
Score 2
Score 3
Score 4
Scale N 3. SILICATES
N Scale 3
SILICATES
Score 1
Score 2
Score 3
Score 4
N Scale 4. GLOBULAR INCLUSIONS
N Scale 4
GLOBULAR INCLUSIONS
Score 1
Score 2
Score 3
Score 4
N Scale 5. POINT INCLUSION
Scale N 5
POINT INCLUSION
Score 1 |
Score 2 |
Score 3 |
Score 4 |
