Keyword: «arc welding»

The purpose of this study is to evaluate the effect of post-weld tempering temperature on changes in the structure and hardness in the heat-affected zone of steel grade 10H9MFB, as well as to assess the effect of post-weld tempering temperature on the hardness and structure of the deposited layers of preliminary surfacing, depending on the technology of manual arc surfacing being performed. The studies carried out confirmed the stability of the properties of the deposited metal with H-6 elec-trodes after tempering. The post-weld tempering temperature of 760 ℃ effectively reduces the hardness in the heat-affected zone of the hot zone, while there is no significant softening of the pre-surfacing metal.

The paper studies welded joints of high-strength pipe steels in twin-arc automatic welding in a shielding gas. The microstructure, transverse and longitudinal macro- and microhardness distribution in various zones of welded joints are studied. Mechanical tests for static tension and impact toughness at low temperatures are carried out. The causes of heterogeneity and the degree of softening in the heat-affected zone are established. The principles of reducing microstructural and mechanical heterogeneity are formulated.