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304 stainless steel plate stretching rupture how to do?

304 stainless steel plate stretching rupture how to do?

Time:2022-03-16 Source:China Wuxi JiaNuo Special Steel Co.

304 stainless steel plate stretching rupture how to do? The following is introduced by JIANUO special steel to you. The current drawing process is commonly used in ferritic stainless steel and austenitic stainless steel. After processing, with the degree of tensile processing, it is possible to have the imagination of cracking in the subsequent. By analyzing the organization and properties of stainless steel materials, such problems can be avoided.

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1, delayed cracking of austenitic stainless steel

As long as the delayed cracking of austenitic stainless steel is determined by its own organization, the degree of processing hardening of austenitic stainless steel is relatively large. In addition to the residual internal stresses generated by cold working, martensitic phase transformation also occurs in some parts of the austenitic organization after stretching. In order to prevent the mouth from cracking, residual stresses and martensite organization must be eliminated, to 304 austenitic stainless steel, for example, the annealing temperature of 1010-1050 degrees Celsius, generally in order to avoid the entire stretching annealing deformation, only the stretching part of the mouth annealing, the faster the high frequency annealing speed.

For cylindrical deep drawing parts, when the height-to-diameter ratio is greater than or equal to 0.8 and the diameter is greater than or equal to 300, annealing is required. Of course, if the height-to-diameter ratio is less than 0.8, there is cracking, and annealing should be arranged immediately.

2, delayed cracking of ferritic stainless steel

Ferritic stainless steel does not undergo phase change after drawing, and product cracking is mainly caused by residual stress. In order to ensure safety, according to experience, for barrel-shaped deep-drawing parts, when the height-to-diameter ratio is greater than or equal to 0.8, the diameter is greater than or equal to 300, the need for annealing treatment. However, if the crack occurs when the height to diameter ratio is less than 0.8, annealing should be arranged immediately.

304 stainless steel plate stretching why rupture, the main reasons are as follows.

1, tensile strength reaches 304 limit.

2, does not meet the tensile requirements of the product.

3, after the initial drawing, 304 hardness increases, continue to draw, not annealed.

304 stainless steel plate cracking is determined by its own structure. Stainless steel has a large degree of work hardening. In addition to the residual internal stresses generated by cold working, austenitic tissue in the mouth after stretching can also occur in the martensitic phase transformation, resulting in cracking. In order to prevent cracking, residual stresses and martensitic organization must be eliminated.