Effects of Arcor Nitrocarburizing Process on the Case Chemistry and Morphology of AISI 1018 Low-Carbon Steel

Industrial modern machinery components, such as gears, bolts, and shafts, are always subjected to continuous frictional wear. The wear resistance and cost of material are the two most important factors while selecting a material for such components. The conventional materials are costly, and there is always a quest for inexpensive materials. The designers mostly choose the low-cost, low-carbon steels. AISI 1018 is one such low-cost, low-carbon grade, which has been used extensively in high-volume screw machine parts applications and is commonly employed in spindles, pins, rods, sprocket assemblies, axles, bolts, connecting rods, motor shafts, hydraulic shafts, pump shafts, and machinery parts. However, the wider applications are restrained by their relatively poor wear and surface properties. This necessitates the need for research on these low-carbon, low-cost materials to address the problem. For decades, surface treatments have been performed to enhance the tribological properties of these components. Salt bath nitrocarburizing is one of the oldest methods and an economical method to improve the tribological properties, as well as the mechanical properties of materials. Unfortunately, in the present literatures, there is not much attention paid on treating AISI 1018 low-carbon steel. A nontoxic salt bath surface modification process nitrocarburizing (Arcor) in ferritic state is investigated on AISI 1018 low-carbon steel. It has been observed that with the increase in nitrocarburizing time and nitrocarburizing temperature, a significant enhancement in mechanical properties, like the hardness of the work material, has been found. Field Emission Scanning Electron Microscope (FESEM) investigations identified compound and diffusion regions on the surface of steel along with line scan elemental intensities.