In recent years, stamping processing plants have continuously promoted the stamping process to reduce costs. For example, the number of deep drawing times for thermos cups and pressure cookers has been reduced from 5 times to 3 times, and the center has been changed from multiple annealing to one annealing or no annealing after stamping is completed. Therefore, higher requirements are placed on the formability of stainless steel materials.

Stainless steel stamping parts sometimes crack when stretched. There are four common types, which occur after tensile deformation, immediately after exiting from the die, when subjected to impact or oscillation after tensile deformation, and after tensile deformation for a period of time or during use. The occurrence of lateral or point-like cracking defects in the sidewalls of stainless steel stamping parts may be the formation of material inclusions, ferrite and other material intergranular defects, or it may be the formation of factors such as deep drawing process and deep drawing oil in the processing of stainless steel stamping parts by stamping processing plants. The lateral or point-like cracking phenomenon of the sidewall of 304 stainless steel drawing parts is mainly caused by inclusions or ferrite present in the material matrix, so the following two points should be well controlled in the production process of stainless steel:

1. Improve the purity of the material and reduce the content of inclusions in the stainless steel matrix.

2. Improve the composition planning and hot and cold rolling annealing process to reduce the content of ferrite in the stainless steel material matrix.

However, due to the inevitable existence of these two production defects in the production process of stainless steel materials in stamping processing plants, appropriate technological measures can also be adopted during the processing of stamped products such as thermos cups and pressure cookers to reduce or prevent cracking caused by inclusions or ferrite defects.

1. Change the forming method from thin drawing to equal thickness drawing.

2. Increase the number of drawing passes, increase the fillet radius of the die, and reduce the deformation difficulty of the material.

3. Appropriately increase the viscosity of the drawing oil to promote uniform deformation of the material and prevent excessive stress concentration.

This article is from EMAR Mold Co., Ltd. For more EMAR related information, please click: www.sjt-ic.com,