HG785高强钢焊接残余应力试验研究

Experimental Study on Welded Residual Stress of HG785 High Strength Steel

利用X-射线法对HG785高强度钢焊接残余应力进行了测试,得到了该材料焊后残余应力的大小及分布规律;并探索了不同深度方向焊接残余应力分布特点。通过试验发现经对接施焊后,表面残余应力主要表现为残余拉应力,最大幅值可达760.4 MPa,为试验件材料屈服强度的92.2%,几乎接近屈服强度。试验结果表明,内部残余应力较表面应力有所降低,在焊缝中心的残余应力值降幅较小;而在远离焊缝中心区域的应力值降幅明显,部分区域甚至出现了残余压应力。

HG785 is a kind of high strength structure steel with good welding behavior. In order to explore the welded residual stress （WRS） distribution of HG785 steel, experiments were taken by the X-ray measurement method. It is shown that most of the WRS belongs to tensile stress on the surface, and the range could up to 760.4 MPa, which is about 92.2% of the yield strength. Meanwhile, the investigation indicates that the WRS reduces with the depth increasing from the surface to inner joint compared with the area near the weld center, from the weld center. area. The WRS decreases more seriously far from the welding and even compressive stress appeared about 10 -15 mm away