The article presents tests concerning the structure and properties of resistance short-circuit welded joints made of 10 mm thick high yield point steel S700MC. The tests revealed the significant effect of a welding thermal cycle leading to less favourable mechanical and plastic properties of the joints. The welding process led to a decrease in tensile strength from 820 MPa (base material strength) to 660 MPa in the joint area. The welded area hardness decreased to 215 HV1, whereas that of the base material amounted to 290 HV1. The hardness in the HAZ area amounted to approximately 235 HV1. The welding process also resulted in a significant decrease in plastic properties. The toughness of the steel dropped from 50 J/cm² (testing temperature being 30°C) to approximately 6 J/cm² in the weld line, approximately 8 J/cm² in the area between the weld and the HAZ and to approximately 11 J/cm2 in the HAZ area. 

doi: 10.17729/ebis.2018.1/4