Steel 7X3

Designation

Name	The value
Designation GOST Cyrillic	7Х3
Designation GOST Latin	7X3
Transliteration	7H3
By chemical elements	7Cr3

Description

7X3 steel is used: for the manufacture of tools (punches, matrices), a hot landing fasteners and blanks made of carbon and low-alloy construction steels in the horizontal forging machines; parts of dies (dies, punches, ejectors) for hot pressing and extruding of these materials on crank presses with small-scale production; bending, trimming and cutting dies.

Standards

Name	Code	Standards
Bars and shapes	В22	GOST 1133-71, GOST 2590-2006, GOST 2591-2006
Sheets and strips	В33	GOST 4405-75
Bars and shapes	В32	GOST 5950-2000, GOST 7417-75, GOST 8559-75, GOST 8560-78, GOST 14955-77, TU 14-11-245-88, TU 14-1-1271-75
Blanks. Of the workpiece. Slabs	В31	OST 24.952.01-89

Chemical composition

Standard	C	S	P	Mn	Cr	Si	Ni	Fe	Cu	V	Ti	Mo	W
GOST 5950-2000	0.65-0.75	≤0.03	≤0.03	0.15-0.45	3.2-3.8	0.1-0.4	≤0.4	Rest	≤0.3	≤0.15	≤0.03	≤0.2	≤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	HRC
- Heat to 650-700 °C. Quenching in oil 850-880 °C + Vacation at 480-500 °C (aging 1 HR)
	-	1620-1710	1670-1760	4-7	16-19	-	40-44
Rolled steel. Quenching in oil with 860-880 °C to + Leave (exposure 2 hours)
	300	≥1650	≥1930	≥4	≥12	-	≥52
Long products (samples). Quenching in oil with 860-880 °C + Vacation at 500 °C (2H exposure)
-	-	≥1240	≥1320	≥10	≥36	-	-
Rolled steel. Quenching in oil from 870 °C to + Leave at 500 °C (exposure 2 hours)
	-	≥1240	≥1320	≥10	≥36	≥370	-
Rolled steel. Quenching in oil with 860-880 °C to + Leave (exposure 2 hours)
	400	≥1440	≥1690	≥5	≥24	-	≥47
Long products (samples). Quenching in oil with 860-880 °C + Vacation at 500 °C (2H exposure)
-	-	≥880	≥1030	≥12	≥34	-	-
-	-	≥780	≥910	≥16	≥55	-	-
-	-	≥550	≥690	≥18	≥68	-	-

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
HRC	Rockwell hardness (indenter diamond spheroconical)

Technological properties

Name	The value
Weldability	does not apply to welded structures.
Склонность к отпускной хрупкости	inclined
The temperature of forging	Start - 1180 °C, the end - of 800 °C. the cross Sections up to 300 mm are cooled in the pit.
Flock-sensitive sensitivity	sensitive