Precipitation Hardening stainless steels are chromium and nickel-containing steels that provide an optimum combination of the properties of Martensitic and Austenitic grades. Like Martensitic grades stainless steels, they are known for their ability to gain high strength through heat treatment and they also have corrosion resistance of austenitic stainless steel. The high tensile strengths of precipitation hardening stainless steels alloys come after a heat treatment process that leads to precipitation hardening of Martensitic or semi austenitic matrix.
Hardening is achieved through the addition of one or more of the elements Copper, Aluminium, Titanium, Niobium, and Molybdenum. The process includes solution treatment, where the material is heated to high temperatures to dissolve soluble phases, followed by rapid cooling to room temperature. This step ensures a uniform distribution of alloying elements and prepares the material for subsequent aging.
Aging temperatures, annealing temperatures, and cooling to room temperature are all part of the process that affects the final mechanical properties, including yield strengths. Solution treatment is also important in achieving the required properties, with the material being rapidly cooled after heating to high temperatures for optimal performance.