高强钢S690QL激光焊接接头晶粒尺寸测定

Measurement of Grain Size of Laser Welded Joint of High Strength Steel S690QL

利用激光焊接方法,制备了S690QL焊接接头。以焊接接头为研究对象,采用图像处理软件IPP分别对母材、相变重结晶区(细晶区)、过热区(粗晶区)、焊缝进行晶粒尺寸的测量。结果表明:母材的平均晶粒尺寸为22.6μm,相变重结晶区(细晶区)的平均晶粒尺寸为11.3μm,过热区(粗晶区)的平均晶粒尺寸为53.6μm,焊缝的平均晶粒尺寸为270.8μm。焊接接头硬度的最大值出现在细晶区。

The S690 QL welded joint was prepared by laser welding method.The welded joint was used as the research object.Image processing software IPP was used to measure the grain size of the base material,transformation recrystallization zone(fine grain zone),overheated zone(coarse grain zone)and the weld.The results show that the average grain size of the base material is 22.6μm,the average grain size of the transformation recrystallization zone(fine grain zone)is 11.3μm,and the average grain size of the overheated zone(coarse grain zone)is 53.6μm.The average grain size of the weld is 270.8μm.The maximum hardness appears in fine grain zone.