The use of nitriding to enhance wear resistance of cast irons

Abstract

This research is focused on using nitriding to enhance the wear resistance of austempered ductile iron (ADI), ductile iron (DI), and gray iron (GI). Three gas nitriding processes, namely "Gas nitriding + nitrogen cooled down to 800 o F" (Blue), "Gas nitriding + cooled down to 300 o F" (Gray), and "Gas nitriding + oil quenched" (Oil) were used. This study was carried out through optical metallography, roughness measurements, microhardness, and SEM. The ball-ondisc wear tests were conducted under lubricated conditions. It was found that COF for all materials in all nitrided conditions was small (<0.045). The best wear performance was seen for ADI processed using the Gray and Oil gas nitriding processes. These processes produced a compound layer thickness of 4-6μm, a low surface roughness (0.8-1.3 μm, Ra) and a high surface microhardness (1800-2200 HV). The wear rate decreased with increasing surface microhardness and decreasing surface roughness.

Effects of plasma nitriding process on the corrosion behavior of GJS700 nodular cast iron

“…Sokolov et al [9] reported that when gray cast iron was exposed to the ion nitriding process, the corrosion resistance of specimens would be increased in 0.7 M NaCl solution. Yang [10] used the nitriding process to improve the wear resistance of cast irons. It was found that the friction coefficient of cast irons in the presence of the compound layer would be reduced to a value of 0.04.…”

Simulation Modeling of Barrel Bore Wear under Dynamic Pressure Load

“…Wear is affected by a variety of conditions, such us the type of lubrication, loading, speed, temperature, materials, surface finish and hardness. For example, nitrided steels are widely used due to their superior hardness and attractive surface hardness, fatigue life and tribological properties [1]. The prediction of wear is therefore an important part in mechanical engineering.…”