焊接热循环对连铸钢中心冲击韧度的影响

Effect of welding thermal cycle on toughness of continuous cast-ing steel center

摘要: 在连铸10CrNi3MoV低合金高强钢表面和心部位置分别取样,采用焊接热模拟方法,通过夏比冲击吸收功测定、显微组织及晶粒度观察,分别研究了取样位置、热输入、多次焊接热循环等因素对连铸钢中心冲击韧度的影响。试验结果表明,中心偏析恶化了连铸钢中心部位冲击韧度,焊接热循环参数对冲击韧度有较大影响。出现上述现象的物理及冶金因素分别是连铸钢中合金元素特别是C,S元素的偏析及不同焊接热循环条件下,热模拟HAZ具有不同的显微组织及晶粒度。

Abstract: Using welding thermal simulation, the effect of weld-ing thermal cycle on impact toughness was investigated by means of charpy impart test and metalographic test, whose specimens were samplinged from surface and center of continuous casting 10CrNi3MoV steel. The results show that center segregation deterio-rates the impact toughenss of center part and the parameter of weld-ing thermal cycle has different effect on toughenss of steel. The rea-sons for physical and metallurgical factor are the element segregation of C and S and the difference in structure and grain size which has subjected to different welding thermal cycle.