Microstructure and Mechanical Properties of Friction Welded Joint of Non-Quenched and Tempered Steel Used for Sucker Rod

In order to provide theoretical foundation and practical technological parameters for used for friction welding super-strength sucker rod,the relationship between friction welding technological parameters and joint mechanical properties of FG-20 steel used for super-strength sucker rod was investigated.With orthogonal testing,mechanical property testing and microstructure analysis,the applicable range and optimized direction of the main technological parameters for friction welding were determined.Because FG-20 steel has high tensile-strength,compared with normal steel,lower welding velocity and larger upset pressure should be adopted.In addition,during the friction welding process,the microstructures and mechanical properties of FG-20 steel HAZ have been changed, so it is special essential to have postweld tempering heat treatment for improving joint mechanical properties.