Assessment of weldability and mechanical properties of VCN150/1.6582 steel joined by resistance butt welding

Abstract

Today, welding methods for joining ferrous and non-ferrous materials have become increasingly popular. However, fusion welding processes face limitations such as the creation of unwanted compounds and thickness limitations, especially when working with special alloy elements, and for this reason, solid state welding methods such as butt resistance method have been considered. In the present study, butt-to-butt resistance welding of VCN steel has been investigated. In this research, in order to investigate the effect of electric current, the welding pressure was considered constant and equal to 20 MPa, and the current was adjusted from about 3000 to nearly 6000 amperes. The results showed that by increasing the current up to 3778 amps, the strength increases by 18%, and then with a further increase in the current up to 5280 amps, the strength decreases. Of course, it should be noted that the percentage of relative length increase does not change significantly in the samples. Also, the results of the microstructural investigation showed that the presence of martensite phase as well as carbides formed in the structure are among the reasons for the increase in hardness in the weld zone in the examined samples.