Precipitation Hardening Stainless Steels | Stainless Steel Types
PH Stainless Steel Grades. Precipitation Hardening (PH) stainless steels are classified as martensitic or semi-austenitic. They develop their high strength and hardness through a variety of heat treatments resulting in a very high strength-to-weight ratio. Semi-austenitic grades are 17-7 PH ® and PH 15-7 Mo ®. They are austenitic in the.