X40CrSiMo10-2, 1.4731, H10S2M - Silchrom valve steel, chromium-silicon, with the addition of molybdenum for valves of internal combustion engines according to PN-71/H-86022 and EN 10090.
| Standard | Steel grade | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chemical Composition % | ||||||||||||
| C: | Mn: | Si: | P: | S: | Cr: | Mo: | Ni: | V: | Ti: | W: | Cu: | |
| PN | H10S2M | |||||||||||
| 0.35 - 0.45 | <0.7 | 1.9 - 2.6 | <0.035 | <0.030 | 9.0 - 10.5 | 0.7 - 0.9 | <0.5 | <0.20 | - | <0.50 | - | |
| EN | X40CrSiMo10-2 - X40CrSiMo10 - X 40 CrSiMo 10-2 - 1.4731 - 4731 | |||||||||||
| 0.35 - 0.45 | <0.8 | 2.0 - 3.0 | <0.040 | <0.030 | 9.5 - 11.5 | 0.8 - 1.3 | <0.5 | - | - | - | - | |
| UNE | F-3221 - X 40 CrSiMo 10-02 - F3221 | |||||||||||
| 0.35 - 0.45 | <0.8 | 2.0 - 3.0 | <0.040 | <0.030 | 9.0 - 11.0 | 0.8 - 1.3 | - | - | - | - | - | |
| AFNOR | Z40CSD10 - Z 40 CSD 10 | |||||||||||
| 0.35 - 0.45 | <0.8 | 2.0 - 3.0 | <0.040 | <0.030 | 9.5 - 11.5 | 0.8 - 1.3 | <0.5 | - | - | - | - | |
| - | 4Ch10S2M - 4Х10С2М - 4Kh10S2M - 4H10S2M | |||||||||||
| 0.35 - 0.45 | <0.8 | 1.9 - 3.0 | <0.030 | <0.030 | 9.0 - 10.5 | 0.7 - 1.2 | - | - | - | - | - | |
| GOST | 40Ch10S2M - 40Kh10S2M - 40H10S2M - 40Х10С2М - ЭЛ 107 - EL 107 | |||||||||||
| 0.35 - 0.45 | <0.8 | 1.9 - 3.0 | <0.030 | <0.025 | 9.0 - 10.5 | 0.7 - 0.9 | <0.6 | <0.20 | <0.20 | <0.20 | <0.30 | |
| GB/T | 4Cr10Si2Mo - S48140 | |||||||||||
| 0.35 - 0.45 | <0.7 | 1.9 - 2.6 | <0.035 | <0.030 | 9.0 - 10.5 | 0.7 - 0.9 | <0.6 | - | - | - | - | |
| MSZ 5776 | SZ4 - SZ 4 | |||||||||||
| 0.35 - 0.45 | 0.3 - 0.6 | 2.4 - 3.0 | <0.010 | <0.030 | 9.0 - 10.5 | 0.8 - 1.2 | <0.6 | - | - | - | <0.30 | |
X40CrSiMo10-2, 1.4731 - specifications and application
H10S2M special valve steel with pearlitic-martensitic structure - heat-resistant up to 900 ℃, and creep-resistant up to approx. 700 ℃.
Mainly used for heavily loaded exhaust valves and loaded inlet valves for aviation, car and motorcycle engines.
The addition of Molybdenum - Mn in relation to H9S2 steel, improves the strength properties, and increases the temperature of resistance to oxidation by 50 ℃.
H10S2M steel is generally not welded.
Mechanical properties of H10S2M
| Mechanical and physical properties at normal temperature | |
|---|---|
| Tensile strength, Rm | ≥ 930 MPa |
| The yield point, Rp0.2 | ≥ 740 MPa |
| Elongation A | ≥ 10 % |
| Density, ρ | ~7,72 kg/dm3 |
| Electrical resistance | 0.90 om mm2/m |
| Specific heat at 20 °C | 0.11 cal/g |
Linear expansion coefficient in the temperature range for H10S2M
| Linear expansion coefficient α | |
|---|---|
| 20 - 100℃ | 10 ⋅10⁻⁶ K⁻¹ |
| 20 - 400℃ | 12.0 ⋅10⁻⁶ K⁻¹ |
| 20 - 500℃ | 12.6 ⋅10⁻⁶ K⁻¹ |
| 20 - 600℃ | 12.9 ⋅10⁻⁶ K⁻¹ |
| 20 - 700℃ | 13.0 ⋅10⁻⁶ K⁻¹ |
| 20 - 800℃ | 13.4 ⋅10⁻⁶ K⁻¹ |
Exemplary strength properties at elevated temperature for H10S2M material
- Steel hardened at a temperature of 1025 ℃ in oil and tempered at 800 ℃
| Temperature | Short-term tensile test and impact strength test | Time creep limit | Modulus of elasticity, E kG/mm2 | ||
|---|---|---|---|---|---|
| Rr (kG/mm2) | a5 (%) | U (kGm/cm2) | R1/10000 | ||
| 20℃ | - | - | - | - | 22000 |
| 500℃ | 67 | - | - | 22 | - |
| 600℃ | 35 - 42 | 15.8 | 17.5 | 2 | - |
| 700℃ | 15 - 22 | 27.6 | 27.5 | 0.25 | - |
| 800℃ | 8 - 12 | 31.2 | 37.5 | - | - |
| 900℃ | ~5 | 48 | 37.5 | - | - |
Thermal conductivity:
- at a temperature of 20 °C - 0.04 cal/cm sec °C
- at a temperature of 600 °C - 0.05 cal/cm sec °C
Heat treatment of X40CrSiMo10-2
H10S2M chromium-silicon steel with the addition of molybdenum is hardened and tempered with cooling in water or air.
After heat treatment, steel acquires tempered martensite structures.
In poor machining, steel is exposed to temper brittleness.
| Heat treatment - process and temperature | ||
|---|---|---|
| Softening annealing at | 900℃ | |
| Hardening | in air or water | 1010 - 1050℃ |
| Tempering at | in oil | 720 - 780℃ |
In the grade of H10S2M the company provides:
- Forgings X40CrSiMo10-2, 1.4731, H10S2M
- Forged bars X40CrSiMo10-2, 1.4731, H10S2M
- Rolled bars X40CrSiMo10-2, 1.4731, H10S2M
The list of equivalents and other designations of H10S2M steel:
X40CrSiMo10-2, X40CrSiMo10, X 40 CrSiMo 10-2, 1.4731, 4731, F-3221, X 40 CrSiMo 10-02, F3221, Z40CSD10, Z 40 CSD 10, 4Ch10S2M, 4Х10С2М, 4Kh10S2M, 4H10S2M, 40Ch10S2M, 40Kh10S2M, 40H10S2M, 40Х10С2М, ЭЛ 107, EL 107, 4Cr10Si2Mo, S48140, SZ4, SZ 4