Influence of Forging Force on Tensile Strength of the 30KhGSA/40KhMFA Steels Welded Joints Made by Rotary Friction Welding

Abstract

This paper presents studies of welded joints of steels 30KhGSA and 40KhMFA made by rotary friction welding. The influence of the forging force on the microstructure and tensile properties of standard specimens and specimens with a notch in the contact zone is analyzed. The results of measuring the microhardness and fractogram of the fracture surface are presented. It has been established that in the selected range of forging forces, the strength of the contact zone is higher than other sections of the thermomechanical affected zone and the base metal of the materials to be welded. In this case, the maximum strength of the contact zone occurs at lower values ​​of the forging force due to the formation of common grains along the contact line as a result of the process of mutual volumetric recrystallization.