Steel 21Н5А (ЭИ56)

Designation

Name The value
Designation GOST Cyrillic 21Н5А
Designation GOST Latin 21H5A
Transliteration 21N5A
By chemical elements 21Н5
Name The value
Designation GOST Cyrillic ЭИ56
Designation GOST Latin EI56
Transliteration EhI56
By chemical elements -

Description

21Н5А steel is used: for the production of long products and forgings intended for fabrication of various critical stressed parts of power plant engineering.

Standards

Name Code Standards
Bars and shapes В22 GOST 1133-71, GOST 2590-2006, GOST 2591-2006, GOST 2879-2006
Bars and shapes В32 GOST 7417-75, GOST 8559-75, GOST 8560-78, TU 14-1-2765-79, TU 14-1-950-74
Blanks. Of the workpiece. Slabs В21 OST 14-13-75
Blanks. Of the workpiece. Slabs В31 TU 1-92-156-90

Chemical composition

Standard C S P Mn Cr Si Ni Fe Cu V Ti Mo W
TU 14-1-2765-79 0.18-0.25 ≤0.025 ≤0.025 0.3-0.6 ≤0.3 0.17-0.37 4.5-5 Rest 0.25 ≤0.05 ≤0.03 ≤0.15 ≤0.2
Fe is the basis.
According to TU 14-1-2765-79 the chemical composition is given for steel grade 21N5A-III.

Mechanical properties

Section, mm sT|s0,2, MPa σU, MPa d5, % y, % KCU, kJ/m2 HB, MPa
Bars hot rolled, forged and calibrated. Quenching in oil with 760-800 °C + Vacation at 150-170 °C, air cooling
≥932 ≥1177 ≥9 ≥40 ≥490 363-444

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
HB Brinell hardness number