Structural steel 40H2MF designed for thermal improvement, surface hardening, for work in high and low temperatures in accordance with PN-89/H-84030-04 standard.
| Standards | Steel Grades | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Chemical Composition % | ||||||||||
| C: | Mn: | Si: | P: | S: | Cr: | Ni: | Mo: | V: | Cu: | |
| PN | 40H2MF | |||||||||
| 0.38 - 0.45 | 0.50 - 0.80 | 0.17 - 0.37 | <0.035 | <0.035 | 1.60 - 1.90 | <0.30 | 0.30 - 0.40 | 0.15 - 0.25 | <0.30 | |
| GOST | 40ChMFA - 40HMFA - 40KhMFA - 40ХМФА | |||||||||
| 0.37 - 0.44 | 0.40 - 0.70 | 0.17 - 0.37 | <0.025 | <0.025 | 0.80 - 1.10 | <0.30 | 0.20 - 0.30 | 0.10 - 0.18 | <0.30 | |
40H2MF, 40ChMFA, 40HMFA - specification and application
Nickel-free, with high hardening capacity grade classified as machine-building steel, high-temperature boiler steel, as well as low-temperature steel, characterized by good ductility, very high durability and good impact resistance in low temperature ranges.
In many cases materials with a particular chemical composition are replaced by chromium-nickel grades (such as 45HN). 40H2MF is a steel which is hardened in oil, but it is possible to obtain optimum mechanical properties with dimensions up to 250mm. It is mainly used in the manufacture of heavy-duty parts and machine components, as steel for shafts, control levers, differential parts, spindles, bolts, axles, crankshafts, connecting rods, cardan shafts and screws.
As a steel for high temperature applications, the products find application in the manufacture of steam turbine shafts, flanges, high pressure cylinders, single and multi-disk rotors, bolts, nuts and screws. Steel is weldable, susceptible to mechanical cutting and, in addition, does not exhibit temper brittleness.
40ChMFA, 40KhMFA, 40ХМФА
Mechanical properties of 40HMF steel
- Tensile strength, Rm > 1230 MPa
- Yield point, Re > 1030 MPa
- Elongation, A > 9%
- Contraction, > 40%
- Notch toughness, KU2 > 40 J
- Hardness in softened state < 241 HB
Mechanical properties for individual dimensions
- Tensile strength Rm
- dimensions 16 - 40mm = 1230 - 1420 N/mm2
- dimensions 40 - 100mm = 1080 - 1230 N/mm2
- dimensions 100 - 160mm = 980 - 1180 N/mm2
- dimensions 160 - 250mm = 880 - 1080 N/mm2
- Yield point Re / Rp0,2
- dimensions 16 - 40mm > 1030 N/mm2
- dimensions 40 - 100mm > 880 N/mm2
- dimensions 100 - 160mm > 780 N/mm2
- dimensions 160 - 250mm > 690 N/mm2
- Contraction Z
- dimensions 16 - 40mm > 40 %
- dimensions 40 - 100mm > 40 %
- dimensions 100 - 160mm > 45 %
- dimensions 160 - 250mm > 45 %
- Elongation A
- dimensions 16 - 40mm > 9 %
- dimensions 40 - 100mm > 10 %
- dimensions 100 - 160mm > 11 %
- dimensions 160 - 250mm > 12 %
- Notch toughness, KU2
- dimensions 16 - 40mm > 40 J
- dimensions 40 - 100mm > 40 J
Heat treatment of 40H2MF steel
- Softening at 680 - 720℃ with slow cooling
- Normalizing at 850 - 870℃ with cooling in air
- Hardening at 830 - 860℃ with cooling in oil
- Tempering at temperatures 500 ° c with cooling in the air