Effects of Cutting Fluid Applications on Surface Integrity in Grinding of Weld Flash in Resistance Welded Alloy Steel

The effect of the grinding process for weld flash removal on the surface integrity of the welded joint has not been researched. The surface integrity of the welded joint is essential for the bandsaw blade life and to prevent any premature failure at the weld joint due to fatigue loading (a band saw blade undergoes mainly cyclic bending fatigue during its service). In this study, the effects of using different cutting fluid combinations on the grinding of weld flash in medium carbon alloy steel were carried out. The use of compressed air as a sustainable solution for grinding weld flash was explored. Experimental investigation of four different cutting fluid applications (dry/no cutting fluid, compressed air, minimum quantity lubricant using vegetable oil, and minimum quantity coolant used water-soluble oil) was carried out. Aluminum oxide grinding wheel at constant cutting speed was used for the study. The surface roughness, sub-surface residual stresses, and microhardness of the ground region were measured for all experimental conditions. This is a first-of-the-kind study on the effect of the flash removal process on the surface integrity of the welded joint. The results show that the surface integrity of the welded joint is significantly influenced by the cutting fluid application used during the grinding process of the flash. This research indicates that it is essential to use cutting fluid during the grinding process of the weld flash. Dry grinding, the current industry standard for grinding weld flash in band saw blades, produced tensile residual stresses, had the highest subsurface thermal damage, and produced the highest surface roughness. In contrast, the sustainable solutions suggested in this research can increase the fatigue life of the ground joint and increase the tool life of the grinding wheels. This study provides the road map for selecting the cutting fluid application for grinding weld flash produced by the resistance welding process in the band sawing industry.