Cracking sometimes occurs in stretched stainless steel pipes, and there are four common types, namely, cracking immediately after stretching deformation, cracking when being hit or vibrated after stretching deformation, cracking after stretching for a period of time or cracking during use.

The main reason is that stainless steel has low ductility, high elastic modulus and high hardening index, and the plastic deformation stage of stainless steel from yield to cracking is relatively short.

Tensile bending of stainless steel

As for the types of stainless steel, the cold work hardening index of austenitic stainless steel is relatively high. Austenitic stainless steel is a metastable material, which will undergo phase transformation during deformation and easily form martensite structure, while martensite is brittle, so it is easy to crack. In the process of plastic deformation, with the increase of austenite phase deformation, the content of martensite phase induced will also increase, and the residual stress will be higher, thus forming a vicious circle, and stainless steel materials are more likely to crack during processing.

Deep drawing, also known as drawing, stretching and calendering, refers to the mechanical processing technology of stamping a flat blank with a certain shape into various open hollow parts or reducing the diameter and increasing the height of the open hollow blank. Customers often have many feedback problems: it is difficult to clean stainless steel after stretching, the lubricity of stainless steel in wire drawing oil is poor, and wire drawing oil is too thick, so stainless steel in wire drawing oil is chosen for cleaning.