20HML
gears, spider, bushings, gears, cylinders, clamps, and other body parts, working for a long time at temperatures up to 500 ° C.
Classification
| Country |
Section |
Category |
| CIS, Russia, Ukraine |
Steels and alloys for castings |
Ordinary steel for castings |
Chemical composition
| Standard |
Fe, % |
Si, % |
Mn, % |
Cr, % |
P, % |
C, % |
S, % |
Mo, % |
|---|
| GOST 977-88 |
97.05–98.45 |
0.2–0.42 |
0.4–0.9 |
0.4–0.7 |
< 0.04 |
0.15–0.25 |
< 0.04 |
0.4–0.6 |
Information on suppliers
Physical characteristics
| Temperature, °C |
$$\alpha\cdot 10^{6}$$, $$K^{-1}$$ |
$$\rho$$, $$\frac{kg}{m^3}$$ |
|---|
| 20 |
|
7800 |
| 100 |
10.9 |
7780 |
| 200 |
12.4 |
7750 |
| 300 |
12.8 |
7720 |
| 400 |
13.1 |
7690 |
| 500 |
13.6 |
7650 |
| 600 |
13.9 |
7620 |
Mechanical properties at 20 °C
| Rolling |
Standard |
Size, mm |
Tension |
Classifiers |
$$\sigma _{U}$$, $$MPa$$ |
$$\sigma_{P}$$, $$MPa$$ |
$$\epsilon_L$$, % |
$$\psi$$, % |
$$KCU\cdot 10^{3}$$, $$\frac{J}{m^2}$$ |
Treatment |
|---|
| Castings |
GOST 977-88 |
< 100 |
|
|
441 |
245 |
18 |
30 |
294 |
Normalization of 880-900 ° C, 600-650 ° C and Holidays |
Brinell hardness number
| Rolling |
Standard |
Classifiers |
Value, HBW |
| Alloy |
|
normalization, average vacation |
149–229 |
Casting and technological parameters
| linear shrinkage, % |
|---|
| 2.2–2.3 |
Technological Properties
| Weldability |
Propensity to temper brittleness |
|---|
| Boundedly welded |
not inclined |
Heat Treatment Modes
| Treatment |
|---|
| Normalization 880 - 890 ° C, Release 600 - 650 ° C |
Analogues
Standards
Description of chemical elements
| Element |
Units of measurement |
Description |
| Fe |
% |
Iron |
| Si |
% |
Silicon |
| Mn |
% |
Manganese |
| Cr |
% |
Chrome |
| P |
% |
Phosphorus |
| C |
% |
Carbon |
| S |
% |
Sulfur |
| Mo |
% |
Molybdenum |
Description of physical characteristics
| Parameter |
Units of measurement |
Description |
| $$\alpha\cdot 10^{6}$$ |
$$K^{-1}$$ |
Coefficient of thermal (linear) expansion (range 20°C–T) |
| $$\rho$$ |
$$\frac{kg}{m^3}$$ |
The density of the material |
Description of mechanical properties
| Parameter |
Units of measurement |
Description |
| $$\sigma _{U}$$ |
$$MPa$$ |
Ultimate tensile strength |
| $$\sigma_{P}$$ |
$$MPa$$ |
Proportionality limit |
| $$\epsilon_L$$ |
% |
Elongation at break (longitudinal) |
| $$\psi$$ |
% |
Reduction in cross section on fracture |
| $$KCU\cdot 10^{3}$$ |
$$\frac{J}{m^2}$$ |
Impact toughness |
Description of the casting and technological parameters
| Parameter |
Units of measurement |
Description |
| linear shrinkage |
% |
The difference between model dimensions and the model casting |
Designation of types of weldability
| Parameter |
Units of measurement |
Description |
| no limits |
|
Welding is performed without heating and without subsequent heat treatment |
| Boundedly welded |
|
Welding is possible with heating up to 100–120 °C and subsequent heat treatment |
| Difficult to weld |
|
For obtaining quality welded joints, additional operations are required: heating up to 200–300 °C for welding, heat treatment after welding — annealing |
| Not applicable for welded structures |
|
|