Solid Solution Treatment of Austenitic Stainless Steel Casting

Austenitic stainless steel casting are heat treated by solid solution treatment and stabilizing treatment to achieve better optimum corrosion resistance.
Austenitic stainless steel is stainless steel having an austenitic structure at normal temperature. When the steel contains about 18% Cr, 8%-10% Ni, and about 0.1% C, it has a stable austenite structure. Austenitic chrome-nickel stainless steel includes the famous 18Cr-8Ni steel and high-Cr-Ni series steel which is developed by adding Cr, Ni content and adding elements such as Mo, Cu, Si, Nb and Ti. Austenitic stainless steel is non-magnetic and has high toughness and plasticity, but its strength is low, it is impossible to strengthen it by phase transformation, and it can only be strengthened by cold working. If S, Ca, Se, Te and other elements are added, it has good machinability. In addition to the corrosion resistance of oxidizing acid medium, such steel can also resist the corrosion of sulfuric acid, phosphoric acid, formic acid, acetic acid, urea, etc. if it contains elements such as Mo and Cu. If the carbon content of such steel is less than 0.03% or contains Ti or Ni, the intergranular corrosion resistance can be remarkably improved. High silicon austenitic stainless steel concentrated nitric acid has good corrosion resistance. Due to the comprehensive and good overall properties of austenitic stainless steels, austenitic stainless steels are widely used in various industries.
Solid Solution Treatment of Austenitic Stainless Steel Casting
The purpose of solid solution treatment of austenitic stainless steel is to completely melt the carbides in the steel and obtain a single-phase structure by heating the casting to 950°C - 1175°C. The heating method should be preheated at a low temperature and then accelerated to The solid solution temperature process is used to reduce the temperature difference between the surface of the steel casting and the core during the heating process. The solid solution holding time is determined by the wall thickness of the steel casting. Generally, the thickness is calculated by the wall thickness of 2.5~3min per mm to ensure the various sections of the casting. All heat can be used, solidified and then quenched into water, oil or air, and water is commonly used, air cooling is only suitable for thin-walled castings.