Heat Treatment Methods For Different Types Of Stainless Steel Pipe Fittings

The heat treatment of Stainless Steel Weld Fittings is to change its physical properties, mechanical properties, residual stress and restore the corrosion resistance affected by the previous processing, so as to obtain better performance of stainless steel pipe fittings or enable stainless steel pipe fittings to withstand further high temperature and low temperature processing. The so-called heat treatment is to carry out corresponding annealing, quenching, tempering, normalizing and other related processing on stainless steel pipe fittings of different structures and types. According to the structure, stainless steel pipe fittings can be divided into austenitic stainless steel, martensitic stainless steel and ferritic stainless steel.

1. Austenitic stainless steel pipe fittings

Austenitic stainless steel pipe fittings are stainless steel pipe fittings with a wide range of uses and large usage. The outstanding feature is the austenitic structure that does not have a phase change at room temperature. It cannot be hardened by heat treatment, but can be hardened by cold working. The commonly used heat treatment method is solution treatment.

2. Ferritic stainless steel pipe fittings

Ferritic stainless steel pipe fittings generally do not have a ν-α phase change, and are ferrite structures that do not have a phase change at high temperature and room temperature. However, when the steel contains a certain amount of austenite-forming elements such as carbon and nitrogen, austenite will also form at high temperatures. This type of steel cannot be strengthened by heat treatment, and can only be annealed to clear internal pressure and promote further surface treatment.

3. Martensitic stainless steel pipe fittings

Martensitic stainless steel pipe fittings have a clear phase transition point, which is the austenite structure at high temperature, and undergoes a martensitic phase transition when cooled, thereby transforming into a martensitic structure and hardening. Because this type of stainless steel pipe fittings contains high chromium and has good hardenability, it can be treated with a variety of heat treatment methods, such as quenching and tempering.