Steel 03Н18К9М5Т (ЭП637; МС200)

Designation

Name The value
Designation GOST Cyrillic 03Н18К9М5Т
Designation GOST Latin 03H18K9M5T
Transliteration 03N18K9M5T
By chemical elements 03Н18Co9Mo5Ti
Name The value
Designation GOST Cyrillic ЭП637
Designation GOST Latin EP637
Transliteration EhP637
By chemical elements -
Name The value
Designation GOST Cyrillic МС200
Designation GOST Latin MC200
Transliteration MS200
By chemical elements MoС200

Description

03Н18К9М5Т steel is used: for the production of bodies of rocket motors, the shafts of helicopters, welded hulls, engines, pressure vessels of large dimensions, details of artillery and small guns, hulls of submarines, submersibles, high-load disc turbines, gears and parts gears, spindles, worms, etc.; heavily loaded machine parts and mechanisms operating in conditions of far North.

Note

Maraging high-alloy, corrosion-resistant, heat-resistant and heat-resistant steel with higher structural stability in the temperature range from cryogenic to +500 °C.

Standards

Name Code Standards
Processing of metals by pressure. Forgings В03 TU 14-1-1530-75, TU 14-1-1531-75
Bars and shapes В32 TU 14-1-3039-80, TU 14-1-1898-76

Chemical composition

Standard C S P Mn Si Ni Fe Cu Al B Ti Mo Co
TU 14-1-3039-80 ≤0.03 ≤0.01 ≤0.01 ≤0.1 ≤0.1 17.7-19 Rest - ≤0.15 - 0.5-0.8 4.6-5.5 8.5-9.5
TU 14-1-1898-76 ≤0.03 ≤0.01 ≤0.01 ≤0.1 ≤0.1 17.7-19 64.797-68.7 Rest ≤0.15 ≤0.003 0.5-0.8 4.6-5.5 8.5-9.5
Fe is the basis.
According to TU 14-1-1898-76 and TU 14-1-3039-80 the chemical composition is given for steel grade 03N18K9M5T (EP637).
According to TU 14-1-3039-80, if steel is smelted by open smelting with subsequent electron-beam remelting, then the carbon content is not more than 0.020% and in this case the steel is marked 02N18K9M5T-EL (EP637A-EL). The calculated content of modifiers and deoxidizers: magnesium, hafnium, cerium, germanium and boron is established by the supplier's technological instructions and their residual content in the metal is not determined by chemical analysis. In the finished product, deviations in the sweat of the norms of chemical composition are permissible: nickel -0.20%, silicon and manganese - not regulated, but the sum of their content should not exceed 0.20% and in this case the steel is marked 02N18K9M5T-EL (EP637A-EL ), sulfur and phosphorus are not regulated, but the sum of their content should not exceed 0.020%. The residual chromium content should not exceed 0.30%.

Mechanical properties

Section, mm sT|s0,2, MPa σU, MPa y, % KCU, kJ/m2
Bars hot rolled and pressed extra virgin in the state of delivery on the other 14-1-1898-76. Quenching + Aging (longitudinal samples)
≥1850 ≥1950 ≥40 ≥350
Bars and rods, hot-rolled 03Н18К9М5Т-VD (ЭП637-VD, ВКС210-VD) TU 14-1-3039-80. Hardening in air, 810-830 °C + Aging at 500-520 °C (extract 3 hours), air cooling
- ≥1913 ≥45 ≥290

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
y The relative narrowing
KCU Toughness

Technological properties

Name The value
Weldability Well welded in thin and massive loft.
Microstructure The macrostructure of the steel on the other 14-1-3039-80 should not have shrinkage and looseness, bubbles, cracks, inclusions, crusts, delamination and placenow visible without using the magnifying devices.