Electron beam welding of oxide dispersion strengthened 9 Cr martensitic steel-an experimental and theoretical perspective

Abstract

Abstract Advanced nuclear energy systems present significant improvements in economics, safety, reliability and sustainability over currently operating reactor technologies. Proper choices of cladding and structural material with a. high neutron damage resistance b. good mechanical properties at high operating temperatures and c. low activation properties are essential for the safe and reliable operation of the system. The 9-12% Cr transformable steels with lower carbon (∼0.1%) contents and addition of Mo, W, V, Nb present better high temperature strength than austenitic steels. The use of 9%Cr steel is considered as an optimum solution taking into consideration the present day requirements like environment, efficiency, elasticity, experience and economy that dominate considerations of modern power station design, layout, fabrication and operation. The pursuit of improved efficiency/power plant performance resulted in the design of system operating at higher temperature and pressure, which requires materials with appropriate high-temperature mechanical properties and metallurgical stability at operating temperatures. Oxide Dispersion Strengthened (ODS) 9% Cr steels have the potential to advance the high temperature performance of associated components in advanced nuclear energy systems with marginal oxidation resistance. The research focuses on Electron beam welding (EBW) of Hot Isostatically Pressed (HIP) ODS 9 Cr martensitic steel in as-received condition to arrive at the optimized weld process parameters. The weldments were characterized using Optical Microscopy for depth of penetration and width of weldments. The experimental results were theoretically verified using Minitab software