Steel A12
Description
Steel A12
Steel A12: a brand of steels and alloys. Below is a systematized information on the purpose, chemical composition, types of supplies, substitutes, temperature of critical points, physical, mechanical, technological and casting properties for the grade — Steel A12.
General information of A12 steel
| Substitute brand |
| Steel A20. |
| Delivery type |
| Circle a12, hexagon a12, Armature a12, long products, including shaped: GOST 1414−75, GOST 2590−71, GOST 2591−71, GOST 2879−69. Calibrated bar GOST 1414−75, GOST 8559−78, GOST 8560−78. Polished bar and silver bar GOST 1414−75, GOST 14955−77. |
| Application |
| axles, rollers, bushings, gear wheels, gears, pins, screws, bolts and other lightly loaded small parts of complex shape, processed for surface quality and dimensional accuracy. |
A12 steel chemical composition
| Chemical element |
% |
| Silicon (Si) |
0.15−0.35 |
| Manganese (Mn) |
0.70−1.10 |
| Sulfur (S) |
0.08−0.2 |
| Carbon (C) |
0.08−0.16 |
| Phosphorus (P) |
0.08−0.15 |
Mechanical properties of A12 steel
Mechanical properties
| Heat treatment, delivery condition |
Section, mm |
σ 0.2, MPa |
σ B, MPa |
δ 5 ,% |
ψ,% |
HB |
HRC e |
| Hot rolled steel |
100 |
|
410 |
22 |
34 |
160 |
|
| Calibrated work-hardened steel |
thirty |
|
510 |
7 |
|
217 |
|
| Calibrated work-hardened steel |
30−100 |
|
460 |
7 |
|
217 |
|
| Liquid carburizing 860−880 ° C. Hardening 860−880 ° C, water. Vacation 180−220 ° С, air. |
| |
fifteen |
290 |
440 |
|
36 |
|
57 |
| Cyanidation 820−860 ° C. Hardening 820−860 ° C, water. Vacation 180−220 ° С, air. |
| |
fifteen |
290 |
440 |
|
36 |
|
57 |
Mechanical properties at elevated temperatures
| test t, ° C |
σ 0.2, MPa |
σ B, MPa |
δ 5 ,% |
| Annealing 840 ° C. |
| 20 |
290 |
440 |
36 |
| 400 |
170 |
400 |
34 |
| 480 |
165 |
315 |
38 |
| 535 |
140 |
255 |
42 |
| 590 |
98 |
185 |
56 |
Mechanical properties depending on the degree of deformation
| Heat treatment, delivery condition |
σ 0.2, MPa |
σ B, MPa |
δ 4 ,% |
ψ,% |
HB |
| Deformation degree — 5% |
450 |
550 |
21 |
50 |
159 |
| Deformation degree — 10% |
530 |
600 |
17 |
47 |
189 |
| Deformation degree — 20% |
640 |
680 |
fourteen |
43 |
229 |
| Deformation degree — 25% |
680 |
710 |
thirteen |
42 |
235 |
Technological properties of steel A12
| Forging temperature |
| The beginning is 1200, the end is 850. |
| Weldability |
| not applicable for welded structures |
| Machinability by cutting |
| HB 167−217, K υ tv.spl. = 1.6 |
| Tendency to release ability |
| not inclined |
| Flock sensitivity |
| sensitive |
Temperature of critical points of steel A12
| Critical point |
° C |
| Ac1 |
735 |
| Ac3 |
866 |
| Ar3 |
840 |
| Ar1 |
685 |
Physical properties of steel A12
| Test temperature, ° С |
20 |
100 |
200 |
300 |
400 |
500 |
600 |
700 |
800 |
900 |
| Normal elastic modulus, E, GPa |
198 |
183 |
|
166 |
|
|
|
|
|
|
| Density of steel, pn, kg / m 3 |
7830 |
|
|
|
|
|
|
|
|
|
| Thermal conductivity coefficient W / (m ° С) |
|
78 |
67 |
|
|
|
|
|
|
|
| Test temperature, ° С |
20−100 |
20−200 |
20−300 |
20−400 |
20−500 |
20−600 |
20−700 |
20−800 |
20−900 |
20−1000 |
| Linear expansion coefficient (a, 10−6 1 / ° С) |
11.9 |
12.5 |
|
13.6 |
14.2 |
|
|
|
|
|
| Specific heat (C, J / (kg ° C)) |
470 |
|
479 |
517 |
|
571 |
|
|
|
|
