Type 15-5 PH is a martensitic precipitation-hardening stainless steel that provides high strength, good corrosion resistance, good mechanical properties at temperatures up to 600°F (316°C) and good toughness in both the longitudinal and transverse directions in both base metal and welds. Short-time, low-temperature heat treatments minimize distortion and scaling. Type 15-5 PH is the ferrite-free version of Type 17-4 PH stainless steel.
15-5 PH Stainless Steel is used in applications that require high transverse strength and toughness such as engine parts, aircraft components, nuclear reactor components etc.
Strictly speaking, stainless doesn’t rust, but like all materials, there are some environments which are just too corrosive and it will be attacked. When stainless is attacked, the corrosion product looks just like the rust you get on carbon steel.
The 15-5 PH alloy is further strengthened by a relatively low temperature heat treatment which precipitates a copper containing phase in the alloy. 15-5 PH is also referred to as XM-12 in some specifications.
15-5 PH stainless steel offers excellent transverse notch toughness and ductility, and a very good uniformity of properties. It displays exceptional resistance to oxidation at high temperatures (up to 1,100°F/593°C). This material is chemically balanced to create an essentially ferrite-free microstructure, giving it a high degree of workability.