13.手工电弧焊SS400钢焊接接头组织及硬度研究

韩娜¹，麻永林¹，陈重毅¹，邢淑清¹，陆恒昌¹， 王文 君²

（1.内蒙古科技大学材料与冶金学院，内蒙古 包头市014010；2.包钢西北创业有限公司 包钢设计研究院，内蒙古 包头014010）

关键词：手工电弧焊；SS400；热输入；显微组织；显微硬度

中图分类号：TG406；TG142.1     文献标识码：A

摘要：采用不同热输入的手工电弧焊对 8mm 厚SS400钢板进行焊接性试验，并通过金相观察和显微硬度测定得到了接头显微组织分布及硬度变化规律。试验结果表明，当焊接热输入为16KJ/cm时，焊接接头存在未焊透的现象；随焊接热输入的增加，热影响区的宽度从 1.9mm 增大到 4.3mm ，粗晶平均直径也略有增大；热输入达到27KJ/cm时，焊缝组织得到较多的针状铁素体，但过热粗晶区晶粒粗大，占整个热影响区的比例达到了52%；不同热输入下各区域的显微硬度较母材均有所提高，热输入为27KJ/cm时，焊缝硬度较母材增大30%左右，达到最大增幅。

Research on Microstructure and Micro-hardness in Welded Joints of SS400 usingshielded metal arc

HAN-na¹, MA Yong-lin¹, CHEN Zhong-yi¹, XING Shu-qing¹, LU Heng-chang¹，WANG wen-jun²

（1.School of Material and Metallurgy, Inner Mongolia University of Science and Technology, Baotou014010, Inner Mongolia Autonomous Region, China; 2.Baogang Design & Research Inst, Baogang Northwest Venture Industrial Development Co., Ltd,Baotou 014010,China）

Key words: Shielded metal arc; SS400; Heat input; Microstructure; Micro-hardness

Abstract: Shielded metal arc welding method with different heat input was used to carry on the welding tests for the 8mm SS400 plate. The microstructure and micro-hardness distribution in welded joints were analyzed through metallographic microscopes and micro-hardness tester. The results show that the welded joint hadn’t been completely penetrated when the heat input came to 16KJ/cm. The width of HAZ ranges from 1.9 mm to 4.3 mm and the average diameters of the coarse grain increase slightly as well with the increasing of heat input. When the heat input came to 27KJ/cm, more acicular ferrite are got in the weld zone, but the grains in the Coarse-grain region grow bigger, accounting for 52 percent of the whole HAZ. The micro-hardness distribution varies every different zone with the improvement of welding heat input. When the heat input came to 27KJ/cm, the micro-hardness in weld zone increases approximately 30% than the base mental.