Forging and heat treatment of the end cap

Forging is used for the forming and processing of mechanical parts, workpieces, tools, or blanks. It primarily involves applying external force to metal blanks to induce plastic deformation, alter their size and shape, and improve their properties.

During low-temperature forging of end caps, the dimensional changes of the forgings are very small. Stainless steel end caps forged below 700℃ exhibit minimal scale formation and no decarburization on the surface. Therefore, as long as the deformation energy is within the forming energy range, cold forging easily yields excellent dimensional accuracy and surface finish. With proper control of temperature and lubrication/cooling, warm forging of threaded pipe fittings, butt-welded pipe fittings, and stainless steel pipe fittings below 700℃ can also achieve excellent accuracy. During hot forging, due to the low deformation energy and resistance, large forgings with complex shapes can be produced. To obtain forgings with high dimensional accuracy, hot forging can be performed in the temperature range of 900-1000℃.

Stainless steel end caps still contain a small amount of carbides after hot working. To improve corrosion resistance, they can be heated to around 1100℃ to dissolve all the carbides into the austenite, and then rapidly quenched in water to room temperature. This heat treatment, known as solution treatment, improves the corrosion resistance of the material and softens the steel. Due to their special shape, improper cooling methods can easily lead to insufficient solution treatment or severe deformation, directly affecting product quality.