Study on the Influence of 8Cr4Mo4V Bearing Steel Hardness on Wear Evolution Under High Temperature Conditions

LI Xinglong; QIU Ming; SUN Dong

doi:10.15926/j.cnki.issn1672-6871.2026.01.008

Abstract：To reveal the influence of hardness on the wear evolution law of 8Cr4Mo4V bearing steel under high-temperature conditions,8Cr4Mo4V bearing steel samples with different room-temperature hardness were prepared by adjusting the tempering temperature.Friction and wear tests were conducted at 25 ℃,150 ℃,and 300 ℃ under a load of 10 N and a sliding speed of 0.5 m/s.The evolution of wear mechanisms was analyzed by combining friction coefficient measurement,wear morphology observation,and energy spectrum analysis(EDS)characterization.The results show that at 25 ℃,the wear mechanism is dominated by abrasive wear.With the decrease in hardness,the wear resistance of the worn surface decreases with the occurrence of slight material transfer,and the wear mechanism transforms from single abrasive wear to abrasive-adhesive wear,and finally to severe abrasive-adhesive wear.At 150 ℃,the wear mechanism is similar to that at 25 ℃;however,high temperature causes slight softening of the bearing steel surface and a decrease in contact stress,resulting in a lower wear degree.The wear mechanism evolves from mild abrasive wear to mild abrasive-adhesive composite wear.At 300 ℃,the high-hardness sample exhibits contact-concentrated abrasive wear due to contact stress concentration,with wear concentrated in the central part of the contact area.The low-hardness sample undergoes intensified wear,leading to significant material adhesion on the surface,which forms a metal oxide layer through high-temperature oxidation.Its wear mechanism transforms into severe abrasive-adhesive-high temperature oxidative composite wear,where the metal oxide layer plays a key role in reducing friction and wear.