Steel 55S2

Designation

Name	The value
Designation GOST Cyrillic	55С2
Designation GOST Latin	55C2
Transliteration	55S2
By chemical elements	55С2

Description

Steel 55S2 is used: for the manufacture of hot rolled plates; coil springs and leaf springs used in automobile and tractor industry, railway transport and other branches of engineering.

Note

Steel spring alloy.

Standards

Name	Code	Standards
Sheets and strips	В23	GOST 103-2006
Bars and shapes	В22	GOST 1133-71, GOST 2590-2006, GOST 2591-2006, GOST 2879-2006
Steel wire medium and high carbon	В72	GOST 26366-84
Sheets and strips	В33	GOST 4405-75, TU 14-1-1409-75, TU 14-1-1986-77, TU 14-130-278-96
Bars and shapes	В32	GOST 7417-75, GOST 7419-90, GOST 8559-75, GOST 8560-78, GOST 14955-77, GOST 14959-79, TU 14-1-2118-77, TU 14-11-245-88, TU 14-136-367-2008

Chemical composition

Standard	C	S	P	Mn	Cr	Si	Ni	Fe	Cu
GOST 14959-79	0.52-0.6	≤0.035	≤0.035	0.6-0.9	≤0.3	1.5-2	≤0.25	Rest	≤0.2

Fe is the basis.

Mechanical properties

Section, mm	t отпуска, °C	s_T\|s_0,2, MPa	σ_U, MPa	d₅, %	y, %	KCU, kJ/m²	HB, MPa	HRC
Hot-rolled sheet. Normalization at 840 °C
80	-	≥370	≥690	-	≥35	-	≤197	-
Samples 17-22 mm. Annealing at 900 °C (extract 2 h) + Quenching in oil from 850 °C + Vacation (excerpt 2 h) cooling furnace
-	300	≥1960	≥2250	≥5	≥20	-	-	-
Sheet. Isothermal quenching from 870 °C and cooled in molten salt (tсоли=300 °C)
3.9	-	≥1220	≥1640	-	-	-	-	≥47
Samples 17-22 mm. Annealing at 900 °C (extract 2 h) + Quenching in oil from 850 °C + Vacation (excerpt 2 h) cooling furnace
-	400	≥1670	≥1830	≥8	≥39	-	-	-
Sheet. Isothermal quenching from 870 °C and cooled in molten salt (tсоли=360 °C)
3.9	-	≥1110	≥1350	-	-	-	-	≥42
Samples 17-22 mm. Annealing at 900 °C (extract 2 h) + Quenching in oil from 850 °C + Vacation (excerpt 2 h) cooling furnace
-	500	≥1270	≥1350	≥12	≥39	-	-	-
-	600	≥830	≥1080	≥15	≥42	-	-	-
Rolled steel. Annealing at 750-780 °C, cooling with the furnace
-	-	≥440	≥760	≥21	≥42	≥157	≤222	-
Rolled steel. Steel categories: 3, 3A, 3B, 3C, 3D, 4, 4A, 4B. Quenching in oil or water from 870 °C to + vacation at 470 °C
	-	≥1175	≥1270	≥6	≥30	-	-	-
Rolled steel. Quenching in oil from 870 °C to + Vacation
-	350	≥1860	≥2030	≥7	≥31	≥226	-	≥50
-	400	≥1830	≥1910	≥9	≥36	≥265	-	≥48
-	450	≥1470	≥1530	≥11	≥46	≥402	-	≥44
-	500	≥1130	≥1220	≥12	≥47	≥471	-	≥41
-	550	≥1060	≥1180	≥13	≥50	≥549	-	≥34

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
y	The relative narrowing
KCU	Toughness
HB	Brinell hardness number
HRC	Rockwell hardness (indenter diamond spheroconical)

Physical characteristics

Temperature	Е, HPa	G, HPa
0	196	78

A description of the physical symbols

Name	Description
Е	The normal elasticity modulus
G	Modulus of elasticity shear torsion
r	Density
l	Coefficient of thermal conductivity
R	UD. the resistivity

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 - of 800 °C. the cooling of the workpiece cross-section up to 250 mm in the air, 251-300 mm - in the pit.
Flock-sensitive sensitivity	not sensitive
Machinability	In hot-rolled condition with HB 255-269 Kn TV.SPL.=0.65 Kn b.St.=0.33