Accelerated Life Testing of Pyrowear 675 Material at 218°C (425°F) Using a Ball-on-Rod Rolling Contact Fatigue Tester

This paper presents the rolling contact fatigue (RCF) life performance of martensitic stainless steel Pyrowear 675 (P675). Two heat treatment versions of P675 were evaluated for RCF life in a hybrid configuration (silicon nitride rolling elements). The results are compared to AISI M50 steel in an all-metal and hybrid configuration. RCF life testing was conducted using a ball-on-rod tester at maximum Hertzian contact stress values of 5.5 GPa (hybrid) and 4.8 GPa (all-metal). Hybrid P675 showed a significant improvement in fatigue life and rolling wear resistance compared to all-metal M50 and hybrid M50. Posttest analysis showed the formation of white etching regions (WERs)/dark etching regions (DERs) and white etching cracks (WECs) in all materials tested. Auger electron spectroscopy (AES) depth profiling showed the presence of a phosphorus-rich film, suggesting material surface reactions with the antiwear additive present in the lubricant.