Improvement measures for surface cracks of small-diameter seamless stainless steel pipes

By formulating reasonable measures to control cracks in the production process of seamless stainless steel pipes, the quality of products can be further improved.

1. Raw material acceptance. Formulate special tube billet procurement technical conditions for small-diameter stainless steel, and make detailed quantitative regulations on inclusion content and outer surface quality. When re-inspecting raw materials, focus on inspecting the inclusion level to prevent defects when processing finished products.
2. Strengthen the grinding of rough pipes. Strengthen visual inspection, mark the defects found, and isolate the defective steel pipes; with the help of auxiliary visual inspection such as endoscopes, locate the defects on the inner wall of the steel pipe, and then adopt fixed-point grinding to grind the defects.
3. Increase non-destructive testing. Formulate reasonable acceptance criteria, conduct ultrasonic flaw detection on steel pipes before cold rolling of finished products, mark and isolate defective steel pipes for flaw detection, and eliminate defects by fixed-point grinding.
4. The same inspection method is used to re-inspect the steel pipes after the above fixed-point grinding. If qualified, they are put into production and used to prevent unqualified products from flowing into the next process.