Stainless steel 420J2 is a medium carbon martensitic stainless steel that achieves high strength, hardness and corrosion resistance through quenching and tempering heat treatment.
420J2 has the following key characteristics:
1. High Hardness: This depends largely on heat treatment, reaching hardnesses of HRC 52-55, with a maximum of HRC 58.
2. Wear Resistance: It exhibits high wear resistance and is commonly used in gears, bearings, cutting tools, and other applications.
3. Corrosion Resistance: It exhibits good corrosion resistance in general environments, especially after polishing or passivation. However, due to its high carbon content, its corrosion resistance is inferior to that of austenitic stainless steel in more demanding environments.
4. Weldability: It is relatively poor and requires immediate heat treatment after welding to prevent cracking. Post-weld heat treatment is often required to restore the material's toughness and corrosion resistance.
5. Magnetic Properties: It exhibits magnetic properties.
420J2 combines strength, hardness, wear resistance, and some corrosion resistance at a relatively low cost. It is widely used in tool manufacturing, medical devices, automotive and mechanical components, chemical equipment, and mold manufacturing.
