SCM 420
SCM 420 Grade Introduction:
SCM420 are alloy steel with high hardenability, temper brittleness, well weldability, less cold cracking tendency, good machinability, and great cold plastic strain. SCM420 generally is used for the parts which need high wear resistance, such as gears, shafts, high-pressure pipes, all kinds of fasteners, and so on. Carburizing structural steel.
SCM 420 Grade Application:
- Gear components of all kinds
- Cogwheels
- Open die steel forgings for general engineering purposes
SCM 420 Equivalent Grades:
| Standard |
Grade |
| GB |
20CrMo |
| JIS |
SCM420 |
| ASTM |
4118 |
| DIN |
25CrMo4 |
SCM 420 Chemical Composition:
| Element |
C |
Mn |
P |
S |
Cr |
Mo |
Ni |
Cu |
Si |
| Content (%) |
0.18-0.23 |
0.60-0.85 |
0.15-0.35 |
≤0.03 |
≤0.03 |
0.90-1.20 |
0.15-0.30 |
≤0.025 |
≤0.03 |
Mechanical Properties:
| Property |
Tensile Strength (σb) |
Yield Strength (σs) |
Elongation Rate (δ5) |
Section Shrinkage (ψ) |
Impact Energy (Akv) |
Impact Toughness Value (αkv) |
Hardness |
| Value |
≥ 885 MPa |
≥ 685 MPa |
≥ 12% |
≥ 50% |
≥ 78 J |
≥ 98 J/cm² |
≤ 197 HB |
Physical Properties:
| Property |
Modulus of Elasticity |
Density |
Thermal Conductivity |
| Value |
210 × 10³ N/mm² |
7.85 g/cm³ |
20.0 W/m·K |
Thermal Properties:
| Property |
Thermal Conductivity |
| Value |
20.0 W/m·K |
Forging Properties:
Hot forming temperature: 1100-850℃
Stress Relieving:
After the final cold drawing, there is a stress relief heat treatment in a controlled atmosphere.