Analysis of Causes for Surface Crack of Small-sized Stainless Steel Seamless Tube

Analyzed are the causes for the surface crack of the Φ10 mm×1 mm 0Cr18Ni9 stainless steel tube.Accordingly corrective actions are put forward.It is regarded via the analysis that it is the inclusions as getting into the round billet during the melting or the casting process that lead to occurrence of some crack which in turn further expands during the cold-rolling deformation process,and eventually becomes the crack through the wall thickness direction.Therefore it is suggested to inspect the inclusion level,when performing acceptance-check of the billet,improving the grinding-repair of the tube,and introducing the NDT procedure,etc.so as to properly control the occurrence of the crack during the production process of the seamless stainless steel tube.