Optimizing the Characteristics of the Laser Hardfacing Process Parameters to Maximize the Wear Resistance of Ni-Based Hard-Faced Deposits Using the RSM Technique

Abstract

The nickel-based Colmonoy-5 hardfacing alloy is used to hard-face 316LN austenitic stainless steel components in fast reactors. The nominal composition (in wt%) was listed as follows: 0.01 C, 0.49 Si, 0.87 Mn, 17.09 Cr, 14.04 Ni, 2.56 Mo, 0.14 N, and balance Fe. Hardfacing is a technique of applying hard and wear-resistant materials to substrates that need abrasion resistance. The thickness of hardfacing deposit varies between 0.8 mm and 2 mm based on parameter combinations. In this study, laser hardfacing process parameters including laser power, powder feed rate, travel speed, and defocusing distance were optimized to reduce weight loss of laser hard-faced Ni-based deposit. The tribological characteristics of reactor-grade NiCr-B hard-faced deposits were investigated. The RSM technique was used to identify the most important control variables resulting in the least weight loss of the nickel-based alloy placed on AISI 316LN austenitic stainless steel. Statistical techniques like DoE and ANOVA are utilized. Changing the laser settings may efficiently track the weight loss of laser hard-faced nickel alloy surfaces. These are created using the response surface technique. The deposit produced with a laser power of 1314 W, powder feed rate of 9 g/min, travel speed of 366 mm/min, and defocusing distance of 32 mm had the lowest weight loss of 16.4 mg. Based on the F value, the powder feed rate is the major influencing factor to predict the hardness followed by power, travel speed, and defocusing distance.