Heat treatment of stainless steel pipe fittings

The purpose of heat treatment of stainless steel is to change its physical properties, mechanical properties, residual stress and restore its anti-corrosion ability which is affected by the previous processing, so as to obtain the best use performance of stainless steel or to enable the further cold hot processing of stainless steel. The so-called heat treatment refers to the corresponding annealing, quenching and tempering, normalizing and other related treatment for different structures and types of stainless steel.

According to the structure, stainless steel can be divided into austenitic stainless steel, martensitic stainless steel and ferritic stainless steel. In order to avoid the deformation of stainless steel surface during heat treatment, the heat treatment methods of these three types of stainless steel are different according to their respective structures and characteristics.

1. Austenitic stainless steel

Austenitic stainless steel is the most widely used. Its characteristic is that austenite structure will not change phase at room temperature, and it can not be hardened by heat treatment, but it can be hardened by cold working. The common heat treatment method is solution treatment.

2. Ferritic stainless steel

In general, ferritic stainless steel does not have V - α phase transformation, and it is ferritic structure without phase transformation at high temperature and normal temperature. However, when there are a certain amount of carbon, nitrogen and other austenite forming elements in the steel, austenite structure can also be formed at high temperature. This kind of steel can not be strengthened by heat treatment, but can only be annealed to eliminate internal stress and facilitate further surface treatment.

3. Martensitic stainless steel

Martensitic stainless steel has obvious transformation point, which is austenite structure at high temperature. When it is cooled, martensitic transformation will take place, and then the martensitic structure will harden. Due to its high chromium content and good hardenability, this kind of stainless steel can be heat treated by many methods, such as quenching and tempering.

The above is the summary of small stainless steel heat treatment methods and characteristics. The quality control in the surface treatment of stainless steel pipe fittings is very strict and prudent. We conduct surface treatment under the condition of ensuring the precision of the size of stainless steel pipe fittings, and strive for perfection in details.