Sliding wear behaviour of austempered ductile iron, boron steel and AISI 1045 steel of similar hardness: effect of microstructure, yield strength, and strain hardening

A study on dry sliding wear investigated four alloys: fully austenitized ADI (F-ADI), intercritically austenitized austempered ductile iron (I-ADI), hardened and tempered Boron steel (B-Steel), and hardened and tempered AISI 1045 steel (EN-Steel). Despite their similar hardness levels, these alloys differ in composition and microstructure. Testing was conducted using a Ball-On-Disc setup (ASTM G99-05) with a chrome steel ball, maintaining a constant sliding speed of 0.6 m/s and applying loads between 20 and 80 N. This study aimed to understand the influence of yield strength (σy), strain hardening coefficient (n), and microstructure on sliding wear under uniform hardness conditions. The findings indicated a strong connection between sliding wear resistance, strain hardening coefficient, toughness, and yield strength. Wear mechanisms varied slightly among materials; F-ADI and I-ADI exhibited deformed layers with increased hardness and oxide formation, while B-Steel and EN-Steel showed micro-cutting and micro-ploughing. F-ADI's high-carbon austenite film and I-ADI's proeutectoid ferrite contributed to improved wear performance. The hardness of the deformation layer on FADI and I-ADI's worn surfaces highlighted the benefits of strain hardening in dry sliding wear.