Surface modification of low alloy steel by laser melting

Surface modification of low alloy steel (LAS) has been achieved by laser melting and Ni alloying. Specimens of LAS were coated with Ni by PVD and electro-deposition techniques followed by laser beam melting. The Ni coating produced by PVD technique could not produce the requisite alloying during the laser melting. In case of LAS specimens coated electrochemically, the iron-nickel binary alloys of different compositions were formed with varying laser beam traverse speed. The surface alloys produced ranged in composition from 20.8 to 33.6 wt.% Ni, where laser beam speed was varied from 10 to 100 mm/min. The binary alloy containing 20.8 wt.% Ni was produced, at 10 mm/min laser beam speed, with martensite as major harder phase, whereas alloys with higher Ni content, produced at higher laser beam speed, retained soft γ-phase.