Although 4140 steel and 4130 steel both belong to the 41xx series chromium-molybdenum alloy steels under the AISI/SAE system, they still have differences.
- Core Composition: 4130(Carbon:0.28-0.33%) < 4140(Carbon:0.38-0.43%）
- Mechanical Properties: 4140+QT has higher strength(850~1080MPa) and hardness (28~32HRC), but slightly lower toughness; while 4130+QT has lower strength (650~800MPa), but better impact toughness and plasticity.
- Processing Performance: 4130 exhibits superior weldability, cold workability, and machinability; while 4140 has slightly better hardenability and a more significant heat treatment strengthening effect, but poor in welding.
- Applications: 4130 is suitable for manufacturing structural components requiring welding and medium-strength parts subjected to impact loads (such as pipes and low-pressure vessels); while 4140 is suitable for high-strength parts requiring heat treatment strengthening (such as spindles, gear shafts, high-strength bolts, and crankshafts).
Conclusion: The core difference between 4140 steel and 4130 steel stems from their different carbon contents, leading to significant differences in strength, toughness, processing performance, and applications.Learn More