Steel A12
Designation
| Name |
The value |
| Designation GOST Cyrillic |
А12 |
| Designation GOST Latin |
A12 |
| Transliteration |
A12 |
| The chemical elements |
- |
Description
Steel A12 is used: for the manufacture of axles, shafts, bushings, sprockets, gears, fingers, screws, bolts and other lightly loaded small parts of complex shape, treated on the surface quality and dimensional accuracy.
Note
Sulfur carbon steel high machinability.
In accordance with GOST 1414−75 rolled A12 steel is not allowed from 01.01.1991 for use in the newly created and upgraded technology.
Standards
| Name |
Code |
Standards |
| Sectional and shaped rolling |
В32 |
GOST 1414-75, GOST 8559-75, GOST 8560-78, GOST 14955-77, TU 14-1-2378-78, TU 14-11-245-88, TU 14-1-1271-75 |
| Sectional and shaped rolling |
В22 |
GOST 2590-2006, GOST 2591-2006, GOST 2879-2006 |
Chemical composition
| Standard |
C |
S |
P |
Mn |
Cr |
Si |
Ni |
Fe |
Cu |
| GOST 1414-75 |
0.08-0.16 |
0.08-0.2 |
0.08-0.15 |
0.7-1.1 |
≤0.25 |
0.15-0.35 |
≤0.25 |
The rest |
≤0.25 |
Fe is the basis.
In accordance with GOST 1414-75 by the order of the consumer, the sulfur content in steel can be 0.08-0.15%. At phosphorus content ≤ 0.10%, the phosphorus content should be in the range of 0.10-0.20%.
Mechanical characteristics
| Section, mm |
sT|s0,2, MPa |
σB, MPa |
d5, % |
d4 |
y, % |
Brinell hardness number, MPa |
HRC |
| The hot rolled, without heat treatment |
|
- |
≥410 |
≥22 |
- |
≥34 |
≤160 |
- |
| Rolled steel. Annealing at 840 °C |
| - |
≥290 |
≥440 |
≥36 |
- |
- |
- |
- |
| Pre-painted steel sheet (indicated by the degree of deformation) |
| - |
≥530 |
≥600 |
- |
≥17 |
≥47 |
≤189 |
- |
| Rental of calibrated and full hard without heat treatment |
| ≤30 |
- |
≥510 |
≥7 |
- |
- |
≤217 |
- |
| Rolled steel. Annealing at 840 °C |
| - |
≥170 |
≥400 |
≥34 |
- |
- |
- |
- |
| Pre-painted steel sheet (indicated by the degree of deformation) |
| - |
≥640 |
≥680 |
- |
≥14 |
≥43 |
≤229 |
- |
| Rental of calibrated and full hard without heat treatment |
| 30 |
- |
≥460 |
≥7 |
- |
- |
≤217 |
- |
| Rolled steel. Annealing at 840 °C |
| - |
≥165 |
≥315 |
≥38 |
- |
- |
- |
- |
| Pre-painted steel sheet (indicated by the degree of deformation) |
| - |
≥680 |
≥710 |
- |
≥13 |
≥42 |
≤235 |
- |
| Rolled steel. Cyanidation at 820-860 °C + Quenching in water with 820-860 °C + Vacation at 180-220 °C, air cooling or Liquid carburizing at 860-880 °C + Quenching in water 860-880 °C + Vacation at 180-220 °C, air cooling |
| ≤15 |
≥290 |
≥440 |
- |
- |
≥36 |
- |
≤57 |
| Rolled steel. Annealing at 840 °C |
| - |
≥140 |
≥255 |
≥42 |
- |
- |
- |
- |
| Pre-painted steel sheet (indicated by the degree of deformation) |
| - |
≥450 |
≥550 |
- |
≥21 |
≥50 |
≤159 |
- |
| Rolled steel. Annealing at 840 °C |
| - |
≥98 |
≥185 |
≥56 |
- |
- |
- |
- |
Description mechanical marks
| Name |
Description |
| Section |
Section |
| sT|s0,2 |
Yield strength or limit of proportionality with a tolerance for residual deformation of 0.2% |
| σB |
Limit short-term strength |
| d5 |
Elongation after rupture |
| d4 |
Elongation after rupture |
| y |
The relative narrowing |
| HRC |
Rockwell hardness (indenter diamond spheroconical) |
Physical characteristics
| Temperature |
Е, ГПа |
r, кг/м3 |
l, Вт/(м · °С) |
a, 10-6 1/°С |
С, Дж/(кг · °С) |
| 0 |
198 |
7830 |
- |
- |
- |
| 20 |
198 |
7830 |
- |
- |
- |
| 100 |
183 |
- |
78 |
119 |
470 |
| 300 |
166 |
- |
- |
125 |
479 |
| 200 |
- |
- |
67 |
119 |
470 |
| 400 |
- |
- |
- |
136 |
479 |
| 500 |
- |
- |
- |
136 |
- |
| 700 |
- |
- |
- |
142 |
- |
| 600 |
- |
- |
- |
- |
517 |
| 800 |
- |
- |
- |
- |
571 |
A description of the physical symbols
| Name |
Description |
| Е |
The normal elasticity modulus |
| r |
Density |
| l |
Coefficient of thermal conductivity |
| R |
UD. the resistivity |
| a |
The coefficient of linear expansion |
Technological properties
| Name |
The value |
| Weldability |
does not apply to welded structures |
| Propensity to temper brittleness |
tend not |
| Forging temperature |
Start - 1200 °C, the end - 850 °C. |
| Flock-sensitive sensitivity |
sensitive |
| Workability by cutting |
NV 167-217 Kn TV.SPL.=1.6 |
