Transverse cracks appeared in 0Cr18Ni9 stainless steel heads after cold spinning
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The 0Cr18Ni9 stainless steel head has a diameter of φ2600mm and a thickness of 18mm; after cold spinning, flaw detection was carried out on the weld seams. Initially, longitudinal cracks measuring 200mm appeared in the straight sections and the transition zones. After repair, further flaw detection was conducted, and transverse cracks along both sides of the weld seams appeared in the transition zones. The material is fine; I’m not sure what’s going on?
It is usually spun after heat treatment; it should be heat spinning
It’s likely that there is an issue with the heat treatment condition of the stainless steel at the time it left the factory, or there are problems with the welding. Generally, no issues have been encountered for diameters below 2600；
You say the material is fine, but has it been inspected? It’s usually a material issue!
1. Materials: 1) Investigate the sources from which the materials are purchased to verify their reliability； 2) Is it supplied in a solid solution state? ； 2. Processing process: Based on what the poster described, it seems to be a head that is formed through welding: 1) Have the welding joints been polished to be level with the base material? ； 2) Whether the butt weld joint has been subjected to solution treatment or stress relief treatment ； 3) Spinning process: It must be cold spinning forming ； Due to the thickness of the sheet, the feed rate during spinning should not be too high or too fast. 3. As for the cracks that appear after repair, I believe they are caused by residual stresses and thermal stresses at the welding joint; these can be overcome by taking appropriate measures, so I won’t go into detail here!
Are there any photos? Send it over so I can take a look.