BS EN 42CrMo4 Alloy Steel is a common chromium-molybdenum steel that usually used after quenched and tempered, with high intensity, high hardenability. BS EN 42CrMo4 round steel has better performance than 34CrMo4 steel due to the carbon and chromium content is higher. 42CrMo4 alloy steel has higher strength and hardenability. The 42CrMo4 alloy material also has high fatigue strength and good low-temperature impact toughness. The temper brittleness is not obvious.
Although 42CrMo4 steel is more expensive than 41Cr4 steel, it is more preferable in terms of material properties. EN 42CrMo4 alloy engineering steel materials have been widely used in automotive driving elements. Otai Steel is able to supply you prime quality of 42CrMo4 alloy steel materials with wide range.
1.42CrMo4 Alloy Steel Supply Range
42CrMo4 Round bar Sizes: 10mm – 3000mm
Steel 42CrMo4 Flat and Plate: 10mm-1500mm thickness x 200-3000mm width
Other steel shape and sizes available according to your requirements.
Surface condition: Black, rough machined, peeled, turned or other requirements according to your requirements.
2.BS EN 42CrMo4 Alloy Steel Relevant Specifications and Equivalents
| BS EN 10250 | Material No. | DIN | ASTM A29 | JIS G4105 | BS 970-3-1991 | BS 970-1955 | AS 1444 | AFNOR |
| 42CrMo4 | 1.7225 | 38HM | 4140 | SCM440 | 708M40 | EN19A | 4140 | 42CD4 |
3.42CrMo4 Alloy Steel Chemical Composition
| 42CrMo4/1.7225 | C | Mn | Si | P | S | Cr | Mo |
| 0.38-0.45 | 0.60-0.90 | 0.40 max | 0.035 max | 0.035 max | 0.90-1.20 | 0.15-0.30 |
4. DIN 42CrMo4 Alloy Steel Mechanical Properties
| Size Ø mm | Yield stress Rp0.2,N/nn2, min. |
Ultimate tensile Stress, Rm,N/nn2 |
Elongation A5,%, min. |
Hardness HB | Toughness KV, Joule, min. |
||||||||||
| <40 | 750 | 1000-1200 | 11 | 295-355 | 35 at 20ºC | ||||||||||
| 40-95 | 650 | 900-1100 | 12 | 265-325 | 35 at 20ºC | ||||||||||
| >95 | 550 | 800-950 | 13 | 235-295 | 35 at 20ºC | ||||||||||
5. Heat Treatment of 42CrMo4 Steels
Annealing of 42CrMo4 Steels
- Heat steel 42CrMo4 forged steel slowly and thoroughly to 800-850°C;
- Cool slowly in the furnace to the temperature 480°;
- Complete annealing the steel in the air.
Quenched and Tempered (Q+T)
- Heat 42CrMo4 steel slowly to 880°C;
- Soak at this temperature then quench in oil;
- Temper as soon as 42CrMo4 steel reach room temperature (20°C);
- Heat uniformly to the suitable temperature of 560°C;
- Withdraw the 42CrMo4 material from the furnace and cool in the air.
6. Forging of 42CrMo4 Alloy Steel
- Preheat 42CrMo4 engineering steel uniformly and slowly;
- Increase the forging temperature up to 1150-1200°C.
- Always keep the forging temperature above at least 850°C
7.Weldability
Engineering steel 42CrMo4 has only limited weldability. Preheating to 200-300°C is strongly recommended; the upper limit should not be exceeded because of risk for deterioration of the chrome layer.
Alloy steel 42CrMo4 can be friction welded. However, precautions are necessary so as to limit the formation of undesirable microstructures in the welded zone.
8.Application of 42CrMo4 Alloy Steels
EN 42CrMo4 alloy steel is widely used for engineering steel purpose, such as: making various kinds of machinery, automobile, mining spare part, the gearwheel of the engine, the driving gear of supercharger, the connecting rob, the pinchock under the high pressure, parts for power train applications, cold formed fastener components, shafts, gears, drill collars for the oil exploration, etc.
