304 stainless steel belt products wall transverse cracking reasons and countermeasures 304 stainless steel capillary

In the deep drawing process of stainless steel belt products all kinds of cracking phenomenon, including wall transverse or dotted cracking such as temperature, pressure cooker deep drawing of 304 stainless steel products processing common failure forms. Especially in recent years the authors continued efforts to promote products processing process, such as vacuum cup deep drawing, the number by 5 times to the current widely used 3 times, from intermediate annealing many times to stamping or not after the completion of a annealing annealing, with stainless steel material can therefore be forming performance put forward higher requirements. Stainless steel belt products wall transverse or dotted cracking defects may be the material of inclusions, the delta ferrite materials such as intergranular defects, may also be a stainless steel products processing in the process of deep drawing process and factors such as deep drawing oil. 304 stainless steel with a thermos flask wall transverse cracking phenomena or dot matrix mainly by material of inclusions or delta ferrite, so should be controlled in the process of the manufacture of the stainless steel with the following two points: ( 1) Improve material purity, cut down the content of inclusions in the stainless steel belt material matrix. （ 2) Improve the composition design and thermal, annealing process, reduce the stainless steel material of delta ferrite content in the matrix. But because the stainless steel belt material in the process of production will inevitably exist two kinds of manufacturing defect, therefore in the process of vacuum cup and other products processing process can also take appropriate measures to reduce or avoid the defects caused by the inclusion or delta ferrite cracking phenomenon: ( 1) Change the way of forming by thinning drawing to such as thick and deep drawing. （ 2) Increase drawing time, increasing the die fillet radius, reduce degree of difficulty of material deformation. （ 3) Appropriate increase drawing oil viscosity, promote material uniform deformation, avoid stress concentration.