材料期刊网

用XQF-2000型显微图像分析仪对CO2气体保护 焊的高强度钢HQ130粗晶热影响区(CGHAZ)的显微组织构成、区域宽度及晶粒度进行了测定 ，并用透射电镜和电子衍射技术对CGHAZ的精细组织结构作了进一步的研究。结果表明，随 着焊接线能量的增加，HQ130钢CGHAZ的主体组织依次为板条马氏体→板条马氏体+下贝氏体 →板条马氏体+下贝氏体+上贝氏体，晶粒直径逐渐变大。当焊接线能量为22.3 kJ/cm时，奥 氏体晶粒的直径最大达158 μm。应将焊接线能量控制在16 kJ/cm以下，使CGHAZ形成板条马 氏体+下贝氏体组织，避免产生上贝氏体组织，防止晶粒粗化，改善该区域的性能。

The relative phase content, as w ell as the width and grain size of coarse grain heat-affected zone (CGHAZ) for high strength steel HQ130 welded by gas shielded arc welding, have been evaluate d by means of XQF-2000 micro-image analysator.The phase components in the zon e have been studied by means of transmission electron microscope and Electron Di ffraction.The experimental results indicated that the main phase in CGHAZ is ch anged from ML、 ML+BL to ML+BL+Bu and the grain becomes coarse with the increas e of weld heat input, especially, the maximum austenitic grain size is up to 158 μm when q/v=22.3 kJ/cm.By controlling weld heat input under 16 kJ/cm it i s possible to form ML+BL in CGHAZ, without upper bainite and coarse grains, then the performance of the CGHAZ can be improved.