Experimental and numerical investigation on generation characteristics of welding deformation in compressor impeller

This study examined the generation characteristics of welding deformation in compressor impellers obtained via a coupled experimental/numerical approach. Highly accurate control in the manufacturing of the compressor impeller is essential to ensure high performance and to prevent aging failure during operation. However, there are very few studies that discuss the generation characteristics of welding deformation in these components. Thus, in this study, a material model of martensitic stainless steel was first developed based on experimentally obtained properties. The temperature dependence and phase transformation were considered for an efficient welding thermal elastic-plastic analysis. A comparison of the temperature profiles of the welds, welding induced residual stress, and distortion generated on a bead-on-plate welding joint was conducted. This enabled the experimental validation of the developed model. Then, experimental measurements and computational calculations of the welding deformation were performed on a compressor impeller mock-up. The results clarified that the longitudinal shrinkage and angular distortion of the fillet welds in the compressor impeller led to the radial deflection of the impeller cover and discharge closure, respectively. The measurements and calculations showed good agreement. Hence, this paper achieved a more detailed understanding of the generation characteristics of welding deformation in compressor impellers. (C) 2016 Elsevier Ltd. All rights reserved.