40KhN
Responsible connecting rods, cogwheels, rail beams, and large-size mill rolls, etc.
Axles, shafts, connecting rods, gears, shafts excavators, couplings, shafts, gears, spindles, screws, levers, rods, cylinders and other senior-laden parts subject to vibration and dynamical loads, which are requirements of high strength and toughness. The rollers and heavy-rail and structural steel mill for hot rolling metal.
Classification
| Country | Section | Category |
|---|---|---|
| CIS, Russia, Ukraine | Structural steel | Alloyed structural steel |
Chemical composition
| Standard | Fe, % | Si, % | Mn, % | Cr, % | Cu, % | Ni, % | P, % | C, % | S, % |
|---|---|---|---|---|---|---|---|---|---|
| GOST 4543-71 | 95.87–97.52 | 0.17–0.37 | 0.5–0.8 | 0.45–0.75 | < 0.3 | 1–1.4 | < 0.035 | 0.36–0.44 | < 0.035 |
Information on suppliers
Physical characteristics
| Temperature, °C | $$E\cdot 10^{9}$$, $$MPa$$ | $$\alpha\cdot 10^{6}$$, $$K^{-1}$$ | $$\varkappa$$, $$\frac{W}{m\cdot K}$$ | $$\rho$$, $$\frac{kg}{m^3}$$ |
|---|---|---|---|---|
| 20 | 200 | 7820 | ||
| 100 | 11.8 | 44 | 7800 | |
| 200 | 12.3 | 43 | 7770 | |
| 300 | 13.4 | 41 | 7740 | |
| 400 | 14 | 39 | 7700 | |
| 500 | 37 |
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 |
|---|---|---|---|---|---|---|---|---|---|---|
| Rod | GOST 4543-71 | 25 | 980 | 785 | 11 | 45 | 690 | Hardening and tempering |
Brinell hardness number
| Rolling | Standard | Classifiers | Value, HBW |
|---|---|---|---|
| Alloy | GOST 4543-71 | annealing | 207 |
| The bar is hot rolled. | GOST 10702-78 | 1790 |
Technological Properties
| Weldability | Flake Susceptibility | Propensity to temper brittleness |
|---|---|---|
| Difficult to weld | sensitive | inclined |
Critical point temperatures
| Ac1, K | Ac3(Acm), K | Ar3(Arcm), K | Ar1, K | Mn, K |
|---|---|---|---|---|
| 735 | 768 | 700 | 660 | 305 |
Analogues
| USA | Germany |
|---|---|
| G31400 | 1.5711 (40NiCr6) |
Standards
| Standard | Description |
|---|---|
| GOST 4543-71 |
Description of chemical elements
| Element | Units of measurement | Description |
|---|---|---|
| Fe | % | Iron |
| Si | % | Silicon |
| Mn | % | Manganese |
| Cr | % | Chrome |
| Cu | % | Copper |
| Ni | % | Nickel |
| P | % | Phosphorus |
| C | % | Carbon |
| S | % | Sulfur |
Description of physical characteristics
| Parameter | Units of measurement | Description |
|---|---|---|
| $$E\cdot 10^{9}$$ | $$MPa$$ | Elastic modulus |
| $$\alpha\cdot 10^{6}$$ | $$K^{-1}$$ | Coefficient of thermal (linear) expansion (range 20°C–T) |
| $$\varkappa$$ | $$\frac{W}{m\cdot K}$$ | Coefficient of thermal conductivity (the heat capacity of the material) |
| $$\rho$$ | $$\frac{kg}{m^3}$$ | 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 |
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 |
Description of temperatures of critical points
| Parameter | Units of measurement | Description |
|---|---|---|
| Ac1 | K | |
| Ac3(Acm) | K | |
| Ar3(Arcm) | K | |
| Ar1 | K | |
| Mn | K |