利用摩擦焊对700 MPa级超细晶粒钢抽油杆进行焊接。试验结果表明：超细晶粒钢具有良好的摩擦焊焊接性,但需要严格控制其工艺参数。选取焊接工艺参数为摩擦压力60 MPa、摩擦时间3 s、顶锻压力120 MPa、顶锻时间1 s时,可有效抑制晶粒长大。摩擦时间是影响轴向缩短量的最主要工艺参数。超细晶粒钢摩擦焊接头主要由焊缝、热力影响区和热影响区组成。热影响区出现了轻微的晶粒长大,最大晶粒直径为9~11μm；摩擦焊接头HAZ显微硬度较母材降低4．13%,拉伸强度最高可达715 MPa,断面伸长率22%,断面收缩率68%,冲击韧性可达98 J,呈典型的韧性断裂。%Friction welding was used in the welding of sucker rod of 700 MPa grade ultrafine grained steel. Experimental results show that ultrafine grained steel has good weldability of friction welding when the friction welding process parameters are strictly controlled. It indicates that the grain growth can be inhibited effectively when selecting the following experimen-tal parameters: friction pressure of 60 MPa, friction time of 3 s, upset pressure of 120 MPa, upset time of 1 s. Friction time is the most important factor affecting the axial expansion allowance. Ultrafine grained steel friction welding joints are mainly composed of welding seam, thermal-mechanically affected zone ( TMAZ) and heat affected zone ( HAZ) . There is a slight grain growth with the maximum grain diameter of 9-11 μm in the heat affected zone. The performance analysis of welding joint shows that micro-hardness of friction welding joints is lower than that of the base metal of 4. 13%. The tensile strength of the ultrafine grained steel friction welding joint is up to 715 MPa, with the cross section elongation percentage of 22%, the cross section contraction ratio of 68% and the impact toughness of 98 J, which shows a typical ductile fracture.
展开▼
