Effect of scanning speed, nozzle stand-off distance and beam scan-off distance on coating properties of laser surface alloyed 13Cr-4Ni steel
The present work describes an investigation of the effect of 3 different parameters of laser surface alloying—i.e., laser scanning speed (LSS), nozzle stand-off distance (NSOD) and laser beam scan-off distance (LBSOD) on coating height, depth and width. Nickel-based Colmonoy 88 alloy powder has been deposited on 13Cr-4Ni steel by single-step process of laser surface alloying. Laser power and powder feed rate were maintained at 3kW and 25 g/min, respectively. L8 orthogonal array has been designed to study these 3 parameters at 2 levels each. The results of single pass with extent of dilution, surface hardness and microstructures produced by different conditions are presented and discussed. For a specified NSOD and LBSOD, there was a decrease in coating height and depth with increase in LSS. Coating height and depth were not affected much by increase in NSOD. From the present investigation, optimized parameters were identified for enhanced hardness, minimum dilution and desired coating height and coating depth.
KeywordsCoating Height Laser Surface Laser Cladding Powder Feed Rate Martensitic Stainless Steel
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