Precipitation Hardened Alloys are one of the five groups of the Stainless Steel family. Stainless Steel Alloys within this group, offer the optimum combination of properties found in the Austenitic and Martensitic grades of Stainless Steel. Sometimes known as Aged Hardened Alloys, they posses a higher Carbon content in comparison to the Ferritic Stainless Steel group. As a result of higher Carbon content, these alloys can harden through air, oil or water cooling, to improve their strength. In fact, some grades can offer strength properties between three and four times higher than Austenitic Stainless Steel grades, such as 304 and 316.
Other key alloying elements include Aluminium, Titanium, Niobium and Molybdenum, either in combination or on their own. Consequentially, this alloy grade offers manufacturers many superior properties, combining high work hardening rates and very high strengths, superior fatigue properties, good corrosion resistance. Equally there is minimum distortion when heat treated. In addition to these properties, this group of Stainless Steel Alloys, offer good formability.
There are three further subdivisions of Precipitation Hardened Stainless Steel, low carbon martensitic, semi-austenitic and austenitic. The most common alloy grade 17/4PH falls into the Martensitic category. Another common gradeis 17-7PH, a austenitic-martensitic type alloy, which is ideal for Aerospace applications, Spring manufacturing and Surgical instruments.