摘要
采用混合气体(80%Ar+20%CO2)保护焊,对一种Ti-Nb微合金化控轧控冷高强钢板进行了焊接强度实验研究。通过微观组织特征分析,阐述了焊接接头热影响区(HAZ)的软化行为,综合分析了回火态HAZ的脆化机理。结果表明,随焊接热输入增加,粗晶热影响区(CGHAZ)晶粒长大,内部析出相粒子发生回溶现象,接头强度降低;焊接接头回火态强度有所提高,但随回火温度上升,CGHAZ的冲击韧性严重降低,其原因主要与原始组织遗传及碳化物沿晶界析出有关。
The welding strength of Ti-Nb microalloyed high-strength steel welded under mixed gas( 80% Ar and 20% CO2) was investigated. The softening behavior in heat affected zone( HAZ) of the welding joint was clarified and the mechanism of embrittlement for HAZ in tempered welding joints was analyzed by microstructure feature. The results show that the strength of the joints decreases with the increasing welding heat input,which is attributed to growth of grain in coarse grain heat affected zone( CGHAZ) and dissolution of the precipitate particles in the same area. In addition,the strength of tempered welding joints increases. However,with the increasing tempering temperature,the impact toughness of CGHAZ rapidly decreases,due to the inheritance of original microstructure and carbide precipitation along the grain boundaries.
出处
《材料热处理学报》
EI
CAS
CSCD
北大核心
2014年第6期115-120,共6页
Transactions of Materials and Heat Treatment
关键词
热影响区
回火
焊接接头
软化
析出相粒子
heat affected zone(HAZ)
temper
welding joint
softening
precipitate particle
