Microstructural Evolution and Toughness in the HAZ of Submerged Arc Welded Low Welding Crack Susceptibility Steel
Microstructural Evolution and Toughness in the HAZ of Submerged Arc Welded Low Welding Crack Susceptibility Steel
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埋弧焊低焊接裂纹敏感性钢HAZ的显微组织演变和韧性
DOI：
10.1007/s40195-012-0103-7
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发表时间：
2013-02-01
影响因子：
3.5
通讯作者：
Du, Linxiu
中科院分区：
文献类型：
--
作者：
Qiu, Chunlin;Lan, Liangyun;Du, Linxiu
采用光学显微镜和扫描电镜结合电子背散射衍射系统研究了低焊接裂纹敏感性钢焊接热影响区（HAZ）不同分区的显微组织特征。重点研究了焊接接头的显微组织特征与热影响区韧性之间的关系。结果表明，熔合线区（FLZ）试样的韧性远低于细晶热影响区（FGHAZ）试样的韧性。焊缝金属中的粗大夹杂物和粗晶热影响区（CGHAZ）中的大量马氏体-奥氏体组元对FLZ的裂纹萌生能有明显的负面影响。同时，粗大的粒状贝氏体和大的有效晶粒严重降低了裂纹扩展能。相比之下，FGHAZ中的细晶粒在提高韧性方面发挥着关键作用，特别是在提高裂纹扩展能量方面。
Microstructural characteristics of different sub-regions of heat affected zone (HAZ) of low welding crack susceptibility steel weldment were investigated by using optical microscopy and scanning electron microscopy equipped with electron backscattered diffraction system. And the focus was put on the correlation between microstructural characteristics and HAZ toughness of the weldment. The results reveal that the toughness of fusion line zone (FLZ) specimens is much lower than that of fine grained HAZ (FGHAZ) specimens. The coarse inclusions in the weld metal and the large martensite-austenite constituents in the coarse grained HAZ (CGHAZ) have an obvious negative effect on the crack initiation energy of FLZ. Meanwhile, the coarse granular bainite with large effective grain decreases the crack propagation energy seriously. By contrast, fine crystallographic grains in the FGHAZ play a key role in increasing toughness, especially in improving crack propagation energy.