Determination of diffusion kinetics, wear and corrosion behaviour of boro-sintered powder metal AISI 316 stainless steel alloy

Abstract

The study aimed to improve the hardness, wear, and corrosion resistance of powder metal AISI 316 stainless steel alloy using boro-sintering to form FeB and Fe2B compounds on the sample surface at different temperatures and durations utilizing Ekabor II boriding powder. The boride layer thickness was measured, and boron diffusion kinetics were determined. The boron diffusion activation energy was computed at 190.29 kJ & sdot;mol-1 during borosintering. The microhardness test revealed 12.5 times increase in the hardness of the AISI 316 stainless steel substrate. Adhesion tests using Daimler-Benz Rockwell C confirmed adequate substrate-coating adhesion of the formed boride layers. The ball-on-disc method results indicated that the wear resistance of boro-sintered samples exceeded that of unboronized AISI 316 stainless steel by a ratio ranging from 8.32 to 14.17. Corrosion tests of boronized powder metal AISI 316 stainless steel alloy samples were conducted in 3.5 % NaCl solution, demonstrating a 50 % reduction in corrosion rate with the boro-sintering process.