正、回火对P92钢焊缝及母材组织和性能的影响

Effect of normalizing and tempering on microstructure and properties of P92 steel weld and base metal

对P92钢焊件焊缝硬度偏低的原因进行了分析,并研究了焊后正火加回火处理对其组织性能的影响。结果表明:P92钢焊件焊后热处理过程中,焊缝或母材的真实温度超过800℃,显微组织发生了变化,导致焊缝或母材的硬度偏低而温度偏低造成热处理不足,焊缝硬度偏高。通过整体正火加回火处理,焊缝和母材硬度相差不大,但显微组织仍有明显区分;对于无法整体热处理的焊件,不建议进行局部正、回火处理。

The reason of low weld hardness of P92 steel weld was analyzed, and the effect of normalizing and tempering on microstructure and properties was studied. The results show that in the process of postweld heat treatment of P92 steel weldment, the actual temperature of the weld or base metal is over 800 ℃, and the microstructure changes, which leads to the low hardness of the weld or base metal while the lower temperature causes insufficient heat treatment and the higher hardness of the weld. By overall normalizing and tempering, the hardness of the weld and the base metal has little difference, but the microstructure is still clearly distinguished. Local normalizing and tempering are not recommended for the weldment which cannot be normalized and tempered.