Steel 20KH5ML
Designation
Name |
The value |
Designation GOST Cyrillic |
20Х5МЛ |
Designation GOST Latin |
20X5ML |
Transliteration |
20H5ML |
The chemical elements |
20Cr5Mo |
Description
20KH5ML steel is used: for the manufacture of the 1st, 2nd and 3rd groups casting parts of valves of oil refining units operating at temperatures of the working medium from -40 to +650 °C without restriction of the nominal working pressure; furnace doubles, pump casings and other components operating in hot oil environments containing sulfur compounds under pressure at temperatures up to +550 °C; casting parts of valves and actuators to it; for the manufacture of pipes tsentrobezhnolityh for the manufacture of coils of tubular furnaces in the production of ammonia, hydrogen, ethylene, carbon disulphide, etc., operating in the temperature range 760−1060 °C and a pressure of 3.92 MPa (40 kgf/cm2).
Note
Stainless steel in hot oil environments containing sulfur compounds, heat-resistant martensitic class. Heat resistance to +600 °C.
Standards
Name |
Code |
Standards |
Castings with special properties (cast iron and steel) |
В83 |
GOST 2176-77 |
Castings, steel |
В82 |
GOST 977-88, OST 26-07-402-83, TU 26-02-19-75, TU 4112-091-00220302-2006, ST ЦКБА 014-2004 |
Pipes steel and connecting parts to them |
В62 |
TU 1333-047-00220302-02 |
Chemical composition
Standard |
C |
S |
P |
Mn |
Cr |
Si |
Ni |
Fe |
Cu |
Mo |
GOST 977-88 |
0.15-0.25 |
≤0.04 |
≤0.04 |
0.4-0.6 |
4-6.5 |
0.35-0.7 |
- |
The rest |
- |
0.4-0.65 |
GOST 2176-77 |
0.15-0.25 |
≤0.04 |
≤0.04 |
0.4-0.6 |
4-6.5 |
0.35-0.7 |
≤0.5 |
The rest |
≤0.3 |
0.4-0.65 |
Fe is the basis.
According to GOST 977-88 molybdenum can be replaced by titanium in an amount of no more than 0.10%, provided that the parts are operated at a temperature of no more than 425 ° С.
According to GOST 2176-77 the chemical composition is given for steel grade 20Х5МЛ. Deviations from the norms of chemical composition are allowed: for carbon ± 0.020%; for silicon ± 0.10%; on manganese, copper, chromium and nickel ± 0.10% each; by titanium and tungsten ± 0.050% each; by vanadium, molybdenum and niobium ± 0.020% each.
Mechanical characteristics
Section, mm |
sT|s0,2, MPa |
σB, MPa |
d |
y, % |
kJ/m2, кДж/м2 |
The castings are supplied according to GOST 2176-77 |
100 |
≥392 |
≥589 |
≥16 |
≥30 |
≥392 |
Description mechanical marks
Name |
Description |
Section |
Section |
sT|s0,2 |
Yield strength or limit of proportionality with a tolerance for residual deformation of 0.2% |
σB |
Limit short-term strength |
d |
Elongation after rupture |
y |
The relative narrowing |
kJ/m2 |
Toughness |
Technological properties
Name |
The value |
Weldability |
limited weldability |