42CrMo4, 1.7225, AISI 4140, 42CrMoS4, 1.7227, 42CD4, 708M40, 38HM – Throught hardening steel according to DIN EN 10083-3.
Table of content:
| Standard | Steel grade | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chemical Composition % | |||||||||||||||
| C: | Mn: | Si: | P: | S: | Cr: | Ni: | Mo: | ||||||||
| EN | 42CrMo4 - 1.7225 | ||||||||||||||
| 0,38-0,45 | 0,6-0,9 | <0,40 | <0,025 | <0,035 | 0,9-1,2 | - | 0,15-0,30 | ||||||||
| PN | 40HM | ||||||||||||||
| 0,38-0,45 | 0,40-0,70 | 0,17-0,37 | <0,035 | <0,035 | 0,9-1,2 | <0,30 | 0,15-0,25 | ||||||||
| EN | 42CrMoS4 - 1.7227 | ||||||||||||||
| 0,38-0,45 | 0,60-0,90 | 0,10-0,40 | <0,035 | 0,020-0,035 | 0,9-1,20 | - | 0,15-0,30 | ||||||||
| ASTM | AISI 4140 - UNS G41400 | ||||||||||||||
| 0,38-0,43 | 0,75-1,00 | 0,20-0,35 | <0,035 | <0,040 | 0,8-1,1 | - | 0,15-0,25 | ||||||||
| AISI | AISI 4145 - UNS G41450 | ||||||||||||||
| 0,43-0,48 | 0,75-1,00 | 0,15-0,35 | <0,035 | <0,040 | 0,8-1,1 | - | 0,15-0,25 | ||||||||
| EN | 37CrMo4 | ||||||||||||||
| 0,35-0,40 | 0,6-0,9 | <0,3 | <0,025 | <0,025 | 0,9-1,2 | - | 0,15-0,30 | ||||||||
| EN | 43CrMo4 | ||||||||||||||
| 0,40-0,46 | 0,6-0,9 | <0,4 | <0,025 | <0,030 | 0,9-1,2 | - | 0,15-0,30 | ||||||||
| NF | 42CD4 | ||||||||||||||
| 0,39-0,45 | 0,6-0,9 | 0,1-0,4 | <0,035 | <0,035 | 0,9-1,2 | - | 0,15-0,25 | ||||||||
| NF | 40CD4 | ||||||||||||||
| 0,39-0,45 | 0,5-0,8 | 0,2-0,5 | <0,030 | <0,025 | 0,95-1,30 | - | 0,15-0,30 | ||||||||
| BS | 708M40 | ||||||||||||||
| 0,36-0,44 | 0,7-1,0 | - | <0,035 | <0,035 | 0,9-1,2 | <0,4 | 0,15-0,25 | ||||||||
| BS | 709M40 | ||||||||||||||
| 0,36-0,44 | 0,7-1,0 | - | <0,035 | 0,02-0,04 | 0,9-1,2 | <0,4 | 0,15-0,25 | ||||||||
| GOST | 38ChM - 38ХМ | ||||||||||||||
| 0,35-0,42 | 0,35-0,65 | 0,17-0,37 | <0,035 | <0,035 | 0,9-1,3 | <0,3 | 0,2-0,3 | ||||||||
| GOST | 38ChMA - 38ХМА | ||||||||||||||
| 0,35-0,42 | 0,35-0,65 | 0,17-0,37 | <0,025 | <0,025 | 0,9-1,3 | <0,3 | 0,2-0,3 | ||||||||
| JIS | SCM4 | ||||||||||||||
| 0,38-0,43 | 0,60-0,85 | 0,15-0,35 | <0,030 | <0,030 | 0,9-1,2 | <0,25 | 0,15-0,30 | ||||||||
| STAS | 41MoCr11 | ||||||||||||||
| 0,38-0,45 | 0,40-0,80 | 0,17-0,37 | <0,035 | <0,035 | 0,9-1,3 | <0,30 | 0,15-0,30 | ||||||||
42CrMo4, 1.7225, 42CrMoS4, 1.7227, AISI 4140 – description
Structural steel, strong and hardenable. With this steel one can achieve very good properties on the whole cross-section (while quenching in oil, the max diameter is 70mm, for quenching in water it is 50mm). In the surface hardened condition in achieves a hardness of 54-59 HRC on the surface.
The alloy is primarily used for very heavily loaded medium and large parts with strength requirements exceeding the capabilities of 35HM or 34CrMo4 alloys. It is a good alternative to expensive chrome-nickel and chrome-nickel-molybdenum steels. The main applications are axles, shafts, crankshafts, connecting rods, larger spindles for machine tools, chain wheels, motor cylinders, ball pins, multi-spline shafts and other machine parts subject to varying bending and torsional loads and wear.
The steel can be gas cut with oxygen after preheating with acetylene-oxy or propane-butane-oxy flame. It is also possible to cut with a plasma jet. The material must be preheated to 300-400 °C before cutting. After cutting cool in air.
42CrMo4 - Mechanical and Physical Properties
Physical properties
- Density: 7,83 g/cm3
- Specific heat capacity: 0,473 kJ/(kg*K)
- Linear expansion coefficient: 11,2 K-1
- Thermal conductivity: 0,42 kW/(cm*K)
- Electrical resistivity: 0,223 Ω*cm
- Young's modulus: 21,7 kG/mm2
Mechanical properties of 42CrMo4 alloy when quenched and tempered (+QT):
- Round bars:
- General:
- Hardness HRC: 35,0 - 48,5
- Hardness HV: 340-490
- Density: 7,82 g/cm3
- Diameter D: < 16 mm
- Yield strength Re: > 900 MPa
- Tensile strength Rm: 1100-1300 MPa
- Elongation A: > 10 %
- Percent reduction of area Z: > 40 %
- Diameter D: 16-40 mm
- Yield strength Re: > 750 MPa
- Tensile strength Rm: 1000-1200 MPa
- Elongation A: > 11 %
- Percent reduction of area Z: > 45 %
- Impact energy KV: > 35 J
- Diameter D: 40-100 mm
- Yield strength Re: > 650 MPa
- Tensile strength Rm: 900-1000 MPa
- Elongation A: > 12 %
- Percent reduction of area Z: > 50 %
- Impact energy KV: > 35 J
- Diameter D: 100-160 mm
- Yield strength Re: > 550 MPa
- Tensile strength Rm: 800-950 MPa
- Elongation A: > 13 %
- Percent reduction of area Z: > 50 %
- Impact energy KV: > 35 J
- Diameter D: > 160 mm
- Yield strength Re: > 500 MPa
- Tensile strength Rm: 750-900 MPa
- Elongation A: > 14 %
- Percent reduction of area Z: > 550 %
- Impact energy KV: > 35 J
- General:
- Flat products:
- Thickness: < 8 mm
- Yield strength Re: > 900 MPa
- Tensile strength Rm: 1100-1300 MPa
- Elongation A: > 10 %
- Percent reduction of area Z: > 40 %
- Thickness: 8-20 mm
- Yield strength Re: > 750 MPa
- Tensile strength Rm: 1000-1200 MPa
- Elongation A: > 11 %
- Percent reduction of area Z: > 45 %
- Impact energy KV: > 35 J
- Thickness: 20-60 mm
- Yield strength Re: > 650 MPa
- Tensile strength Rm: 900-1000 MPa
- Elongation A: > 12 %
- Percent reduction of area Z: > 50 %
- Impact energy KV: > 35 J
- Thickness: > 100 mm
- Yield strength Re: > 500 MPa
- Tensile strength Rm: 750-900 MPa
- Elongation A: > 14 %
- Percent reduction of area Z: > 55 %
- Impact energy KV: > 35 J
- Thickness: < 8 mm
Mechanical properties of 42CrMo4 alloy when quenched, tempered and cold-drawn (+QT+C):
- Round bars:
- Diameter D: 5-10 mm
- Yield strength Re: > 770 MPa
- Tensile strength Rm: 1000-1200 MPa
- Elongation A: > 8 %
- Diameter D: 10-16 mm
- Yield strength Re: > 750 MPa
- Tensile strength Rm: 1000-1200 MPa
- Elongation A: > 8 %
- Diameter D: 16-40 mm
- Yield strength Re: > 720 MPa
- Tensile strength Rm: 1000-1200 MPa
- Elongation A: > 9 %
- Diameter D: 40-100 mm
- Yield strength Re: > 650 MPa
- Tensile strength Rm: 900-1100 MPa
- Elongation A: > 10 %
- Diameter D: 5-10 mm
Mechanical properties of 42CrMo4 alloy when quenched, tempered, peeled, then cold-drawn and quenched and tempered again (+QT+SH / +C+QT):
- Round bars:
- Diameter D: 16-40 mm
- Yield strength Re: > 750 MPa
- Tensile strength Rm: 1000-1200 MPa
- Elongation A: > 11 %
- Impact energy KV: > 35 J
- Diameter D: 40-100 mm
- Yield strength Re: > 650 MPa
- Tensile strength Rm: 900-1100 MPa
- Elongation A: > 12 %
- Impact energy KV: > 35 J
- Diameter D: 16-40 mm
Mechanical properties when spheroidized, cold drawn and heat treated again (+AC+C+AC)
- Diameter D: 2-5 mm
- Yield strength Re: < 620 MPa
- Percent reduction of area Z: > 60 %
- Diameter D: 5-40 mm
- Yield strength Re: < 610 MPa
- Percent reduction of area Z: > 60 %
Physical and mechanical properties when spheroidized, cold drawn, spheroidized again and skin passed (+AC+C+AC+LC)
- Diameter D: 2-5 mm
- Tensile strength Rm: < 660 MPa
- Percent reduction of area Z: > 58 %
- Diameter D: 5-40 mm
- Tensile strength Rm: < 650 MPa
- Percent reduction of area Z: > 58 %
Heat treatment and working
Recommended working and heat treatment parameters for 42CrMo4 alloy:
- Forging: 1050-850 °C
- Rolling: 1050-850 °C
- Quenching: 820-860 °C / o,w
- Tempering: 540-680 °C
- Normalizing annealing: 840-880 °C
- Soft annealing: 680-720 °C
We deliver this steel alloy as:
- Round, hexagonal Bars and flat bars
- Tubes and Pipes
- Wires
- Forgings
- Sheets and plates
- Coldrolled strips
Steel is classified as part of welding group 5.1 according to ISO/TR 20172. Weld in argon or carbon dioxide shielding.
Steel is hardly weldable, so weld only in special cases. Welding is best carried out when the alloy in an annealed, softening condition. In addition, the steel must be preheated - for elements with a thickness of up to 15 mm to 250-350 °С, and for elements with a thickness of up to 25 mm to 300-450 °С. If the welded part has a lower limit carbon content, is thin and the welding is performed with high current, preheat to a lower temperature within the specified range.
For thicker elements it is recommended to use an intermediate stress relief annealing. Immediately after welding, before the joint cools down, perform soft annealing or tempering.
If the welded part cannot be machined directly after welding, it must be cooled very slowly to ambient temperature. Consider cooling together with furnace, in asbestos mats or in hot sand.
Welding toughened parts will result in an area with worse mechanical properties in the welding heat affected zone. The entire element must be heat treated again to restore its properties.
Steel is suitable for electric, resistance and friction welding. Resistance welding requires higher pressure, lower current and more time than low carbon steels. Weld in tempered or softened condition. After welding and appropriate heat treatment, the mechanical properties of the weld may be similar to the rest of the material.
Replacements, equivalents and other designations:
42CrMo4, 38CrMo4, SCM4, SCM 440, 40HM, 41MoCr11, 42MoCr11, B43, 2244, 4140, 4140M, 4142, 4145, C4732, 38ChM, 37CrMo4, 43CrMo4, 40CD4, 42CD4, 708M40, 709M40, En19, CMo4, 40Cr1Mo28, 40Cr4Mo3, 42CrMoS4, 1.7227, 38ХМА, 38ХМ.