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 sT|s0,2, MPa σU, 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
sT|s0,2 Yield strength or limit of proportionality with a tolerance for residual deformation of 0.2%
σU 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