【摘要】 采用扫描电镜、透射电镜TEM和电子背散射衍射EBSD分析了焊接偏析对纳米贝氏体钢再纳米化焊缝中的残余奥氏体的影响.结果表明,焊接偏析导致了粗大奥氏体的形成,该粗大奥氏体集中分布于枝晶间位置.粗大奥氏体的含碳量低于块状奥氏体,稳定性降低.母材残余奥氏体尺寸为亚微米级且均匀分布,而焊缝残余奥氏体的平均晶粒尺寸为微米级,且分布不均匀.焊接偏析导致的焊缝残余奥氏体的变化对焊缝延伸率有重要影响.力学测试结果表明再纳米化焊缝强度与母材相当,延伸率明显小于母材.更多还原

【Abstract】 Effect of welding segregation on retained austenitein regenerated weld for nanostructured bainite steel has been investigated by SEM,TEM and EBSD. Welding segregation resulted incoarse retained austenite that distributed at the boundary of the dendrite in the weld. The carbon content of coarse re-tained austenite is lower than that of the blocky-shape austenite,which reduces stability of the structure. The retained austenite in base metal is in submicronmeter size with a uniform distribution.By contrary,the size of retained austenite in the weld is in micronmeter,and the distribution is not uniform. As a result,the change of the retained austenite in the weld has important effect on the elongation rate of the weld.更多还原