Designation by Standards
| Steel No. | DIN | EN | AISI | JIS | ГОСТ |
| 1.7225 | - | 42CrMo4 | 4142 | SCM440 | / |
Chemical Composition (in weight %)
| C | Si | Mn | Cr | Mo | Ni | V | W | Others |
| 0.42 | max. 0.40 | 0.65 | 1.05 | 0.20 | - | - | - | - |
Description
This is one of the chromium, molybdenum, manganese low alloy steels noted for toughness, good torsional strength and good fatigue strength.
Applications
Statically and dynamically stressed components for vehicles, engines and machines. For parts of larger cross-sections, crankshafts, gears.
Physical properties (avarage values) at ambient temperature
Modulus of elasticity [103 x N/mm2]: 190-210
Density [g/cm3]: 7.84
Soft Annealing
Heat to 680-720oC, cool slowly in furnace. This will produce a maximum Brinell hardness of 241.
Hardening
Harden from a temperature of 820-850, 830-860oC followed by water or oil quenching.
Normalizing
Normalizing: 840-880oC
Tempering
Tempering temperature: 540-680oC
Mechanical Properties in Quenched and Tempered Condition
| Diameter (mm) | 0.2 % proof stress (N/mm2) | Tensile strength (N/mm2) | Elongation (%) | Reduction of area (%) | Notch impact energy (ISO-V) (J) |
| up to 16 | 900 | 1100-1300 | 10 | 40 | 35 |
| 17-40 | 750 | 1000-1200 | 11 | 45 | 40 |
| 41-100 | 650 | 900-1100 | 12 | 50 | 40 |
| 101-160 | 550 | 800-950 | 13 | 50 | 40 |
| 161-250 | 500 | 750-900 | 14 | 55 | 40 |
Hardenability in the end-quench test (Hardness (HRC) vs. Distance (mm))
| Hardness | 1.5 | 3 | 5 | 7 | 9 | 11 | 13 | 15 | 20 | 25 | 30 | 35 | 40 |
| H max. | 61 | 61 | 61 | 60 | 60 | 59 | 59 | 58 | 56 | 53 | 51 | 48 | 47 |
| H min. | 53 | 53 | 52 | 51 | 49 | 43 | 40 | 37 | 34 | 32 | 31 | 30 | 30 |
| HH max. | 61 | 61 | 61 | 60 | 60 | 59 | 59 | 58 | 56 | 53 | 51 | 48 | 47 |
| HH min. | 56 | 56 | 55 | 54 | 52 | 48 | 46 | 44 | 41 | 39 | 38 | 36 | 36 |
| HL max. | 58 | 58 | 58 | 57 | 56 | 54 | 53 | 51 | 49 | 46 | 44 | 42 | 41 |
| HL min. | 53 | 53 | 52 | 51 | 49 | 43 | 40 | 37 | 34 | 32 | 31 | 30 | 30 |
Forging
Hot forming temperature: 1050-850oC.
Machinability
Machinability of this alloy is good in the annealed condition. In the heat treated and quenched condition machining is best limited to finish grinding.
Corrosion Resistance
This alloy is a steel and is not corrosion resistant. Protective coating must be used in corrosive, or water, environments.
Remark
All technical information is for reference only.