Developing Empirical Relationship to Predict Hardness of the Laser Hardfaced Ni-Based Alloy Surfaces

Nuclear reactor components generally undergo wear damage due to severe operating conditions. The operating temperature of nuclear components generally falls in the range of 573-873 K. Among the reactor components, feed water regulator valves, used to throttle coolant flow, experiences higher wear rate. To enhance the wear resistance, nickel (Ni) and cobalt (Co) based alloys are hardfaced into austenitic stainless steels (ASS) through laser hardfacing technique. Laser hardfacing technique is an established surfacing process to deposit Ni base alloys with minimum dilution. Though lot of research works have been carried out so for to characterize laser hardfaced Ni base alloy surfaces, there is no direct correlation between laser parameters and hardness of the hardfaced surfaces. Hence in this investigation, an attempt has been made to develop empirical relationship to predict hardness of laser hardfaced Ni base alloy surface incorporating laser parameters using statistical tools such as design of experiments (DoE), analysis of variance (ANOVA). The developed empirical relationship can be effectively used to trail the hardness of laser hardfaced nickel alloy surfaces by altering laser parameters.