Effect of salt bath nitriding on tribological properties of AISI52100 steel coatings using RSM

Abstract

This investigation employs the salt bath nitriding to extend the service life and improve the surface characteristics of AISI 52100, commonly employed in bearing applications. A wear test was conducted using a pin-on-disc device according to ASTM G-99 standard, and the findings show a 30% reduction in wear loss. Sliding wear experiments were conducted at 1.5 meters per sec with a 5 N force at room temperature on uncoated and nitrided pins which was obtained as optimum value from RSM. The three variables five levels central composite design (CCD) were utilized in order to reduce the number of trails and the model relations were examined through ANOVA. Surface hardness, friction coefficient, wear coefficient, Loss in wear is measured over pins without coating and nitride pins. Investigations were done into how 5W30 oil affected passive and drip lubrication. Nitride substrates had a hardness of 590 HV. Also, nitriding has a favorable effect on the friction coefficient, lowering it by up to 23%. The 5W30 lubricant will further decrease the friction coefficient. The lowest coefficient of friction was seen with the addition of 14% drip oil lubrication. Significantly less wear loss in the pin was caused by a combination of high hardness and low coefficient of friction.