奥氏体不锈钢中微量元素致焊接缺陷实例分析

Cases analysis of welding defects caused by microelements in austenitic stainless steels

结合在奥氏体不锈钢焊接生产实践中遇到的焊接缺陷,取样进行测试及理论分析。总结了缺陷产生的原因并提出了相应的解决措施,以从根本上避免此类缺陷的产生。这些焊接缺陷具有一个共同的特点,缺陷的产生并不是焊接材料或焊接工艺参数选择错误造成的,而是由于奥氏体不锈钢母材化学成分中微量元素的原因导致的。避免这类焊接缺陷产生的根本措施是母材成分中微量元素的控制及优化,而通过焊接技术难以消除这类焊接缺陷,尤其是采用不锈钢薄板的自熔化焊接工艺的情况。为了从本质上提高不锈钢的焊接性,在材料的成分设计和生产质量控制过程中就应充分考虑到焊接加工性能。

Combined with welding defects in austenitic stainless steel welding practice,the samples were tested and analyzed theoretically.Causes to welding defects were concluded corresponding measures to eliminate welding defects were proposed in order to avoid such defects fundamentally.The defects mentioned had a common feature that the defects were not caused by welding materials or welding parameters,but caused by some inappropriate microelements in the base metal of austenitic stainless steel.The fundamental measures to eliminate the welding defects were to control and optimize microelements in the base metal,while it was difficult to eliminate the welding defects by welding technology,especially in the case of self-melting welding of stainless steel sheet.In order to improve weldability of stainless steel in essence,weldability and workability should be fully considered in the process of material composition design and production quality control.