Steel A12

Designation

Name	The value
Designation GOST Cyrillic	А12
Designation GOST Latin	A12
Transliteration	A12
By 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
Bars and shapes	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
Bars and shapes	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	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 properties

Section, mm	s_T\|s_0,2, MPa	σ_U, MPa	d₅, %	d₄	y, %	HB, 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
s_T\|s_0,2	Yield strength or limit of proportionality with a tolerance for residual deformation of 0.2%
σ_U	Limit short-term strength
d₅	Elongation after rupture
d₄	Elongation after rupture
y	The relative narrowing
HB	Brinell hardness number
HRC	Rockwell hardness (indenter diamond spheroconical)

Physical characteristics

Temperature	Е, HPa	r, kg/m³	l, W/(m · °C)	a, 10^-6 1/°C	С, J/(kg · °C)
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
Склонность к отпускной хрупкости	tend not
The temperature of forging	Start - 1200 °C, the end - 850 °C.
Flock-sensitive sensitivity	sensitive
Machinability	NV 167-217 Kn TV.SPL.=1.6