摘要
The plate rigid restraint cracking tests (PRRC) have been used to study the welding cold cracking susceptibilities of four kinds of domestic HSLA steels and the effects of diffusive hydrogen content. In welded joints, welding heat input, local preheat temperature, restraint intensity and additional stress induced by local preheating on cold cracking susceptibility of steels have been discussed. On the basis of the above research, the critical cooling time criterion tcr of domestic HSLA steels is established. This criterion is proved to be reliable in real application, and has important significance to assess whether the cold cracking occurs under conditions of welding process.
用平板刚性拘束裂纹试验（ＰＲＲＣ）研究了４种国产低合金高强钢焊接冷裂敏感性，探讨了焊接接头扩散氢含量、焊接线能量、局部预热温度、拘束度的大小及局部预热产生附加应力等对钢材冷裂纹敏感性的影响。建立了国产低合金高强钢的临界冷却时间判据ｔｃｒ。实验表明此判据可靠，可用于评定现行焊接工艺条件下是否产生冷裂纹及确定合理的焊接工艺。
