Properties and Structure of 1565ch Alloy in the FSW Zone of Intersection of Welds

Abstract

The results of experimental studies are given for specific formation of the structure of 1565chM alloy in the zone of intersection of welds. The welds are made using friction stir welding (FSW). It is found that the area where two welds intersect features a decrease in the average grain size from 5.2 to 3.3 μm. The measurements made for the moving force of the tool show that, upon moving from the welding section of 1565 chM alloy to the section of intersection with a preliminarily made weld, this value decreases from 11.75 to 3.8 kN. The metal in the area of intersection of two FSW welds has better strength properties. At the same time, the relative elongation is slightly lower here compared to the metal in the single weld stir zone. The static tensile tests reveal the highest strength properties in samples having longitudinal weld orientation relative to the direction of applying the load. Samples with intersecting welds are about 10–15% less strong.