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Effect of solid solution on flanges & stainless steel pipe fittings
Times:[ 2019-11-16 Author:admin Hit:
For stainless steel pipe fittings and flange manufacturers, it is necessary to take into account not only the production cost of flange and pipe fittings, but more importantly, the factors that can prevent corrosion and improve product quality. Therefore, it is recommended to adopt the solid solution for the production process of stainless steel pipe flanges and fittings to enhance the safety of the products. 

The heat treatment process plays a vital role in the quality and safety of the pipe fittings. A small number of enterprises have only taken polishing, blasting treatments to cover the defects and deficiencies of the pipe fittings, without adopting solid solution treatment just for saving their costs, which will bring long-term hidden dangers to the use of pipe fittings.

In the solid solution strengthening process, the austenitic stainless steel is softened by heat treatment, and the stainless steel is heated to about 950 to 1150 °C for a certain period of time so that the carbide and various alloying elements are uniformly dissolved in the austenite.

The effect of heat treatment on stainless steel pipe fittings
After the stainless steel pipe is processed by molding, welding, etc., the molecular structure, magnetic properties and physical properties of the metal will change. The atmosphere protecting solution treatment process can restore the corrosion resistance ability that is affected after the previous processing, and at the same time obtain the hardness required for stainless steel to ensure the best use of it. 

With solid solution treatment, the stainless steel pipe fittings are able to have good improvement effects as follows:
1. Eliminate the chemical modification phenomenon of stainless steel pipe fittings during processing, reduce the hardness of stainless steel to below 220HV, improve the plasticity and toughness of stainless steel, and make the pipe fittings more convenient and safe in installation.
2. Restore stress and intergranular changes in the production process, reduce intergranular corrosion and stress corrosion of stainless steel, and enhance corrosion resistance ability.
3. Remove the magnetic properties generated during processing, and stabilize the austenite structure.
4. Restore the naturally smooth and shiny surface of the stainless steel material.

Characteristics of solid solution for stainless steel pipe fittings
Stainless steel is a special type of steel. Due to the presence of alloying elements such as nickel and chromium, its heat treatment has different characteristics from normal steel heat treatment:
1. The thermal conductivity of stainless steel is low. The thermal conductivity at room temperature is only 27% of that of carbon steel. With the increase of heating temperature, the thermal conductivity of stainless steel is gradually reduced. Therefore, when the stainless steel is heated at a low temperature, the temperature rising process should be carried out slowly.
2. After austenitic stainless steel is heated to about 1100 °C by solid solution, it can inhibit the generation of carbides, and then rapidly cool to room temperature to make the carbon supersaturated, which can greatly improve the corrosion resistance of stainless steel.
3. The pipe fittings are protected by gas (hydrogen) during the solid solution treatment to avoid the formation of viscous iron oxide on the surface of the stainless steel, and to restore the brightness of the stainless steel surface.