Optimization of Dissimilar Friction Welding and Creep Rupture Tests for Nuclear Reactor Component Materials

Abstract

An experimental work of dissimilar friction welding was conducted using 15 mm diameter solid bar in copper alloy (Cu-1Cr-0.5Zr) to stainless steel (STS316L) for being used as fusion reactor component materials, not only to optimize the friction welding parameters, but also to investigate the elevated temperature tensile strength and creep rupture properties for the friction welded joints under the optimal welding conditions. The main friction welding parameters were selected to endure good quality welds on the basis of visual examination, tensile tests, Vickers hardness survey of the bond area and HAZ. For friction weld joining of copper alloy to stainless steel bars, the total upset increases lineally as increasing heating time. Optimal welding conditions were selected as follows: Rotational speed 2000rpm, friction pressure 80MPa, upsetting pressure 140MPa, heating time 2 second, upsetting time 5 second and total upset 13mm. The weld interface of dissimilar friction welded steel bars was mixed strongly. And also the creep properties and creep life prediction by Larson-Miller parameter method were presented at the elevated temperatures of 300, 400 and 500oC.