Precipitation hardening stainless steel grades have higher alloying contents than martensitic grades.
They contain nickel, and in order to achieve hardening by aging additions of copper, aluminum, titanium, niobium and molybdenum.
Depending on chemical composition their microstructure after final heat treatment is austenitic,semi-austenitic or martensitic.
Typical applications e.g. oil field equipment, chemical processing equipment, pump shafts, gears, flanges, valves, springs, aircraft parts.