SUS630 Stainless Steel: Precipitation-Hardening Strength

Grade 630 martensitic precipitation hardening stainless steel has a combination of high hardness and strength after suitable heat treatment. It also has similar corrosion and heat resistance to Grade 304. The terms "Type 630" and "17-4PH" refer to the same grade.

 

Heat Resistance This grade has good oxidation resistance, but to avoid reduction of its mechanical properties and hardness it should not be used above its age hardening temperature. Prolonger exposure in the range 370-480°C should be avoided if ambient temperature toughness is critical. Heat Treatment Solution Treatment (Condition A) Heat at 1040°C for ½ hour and cool to 30°C maximum in air. Oil quenching may be used for small non-intricate sections.