Effect of different coatings on friction wear performance and corrosion resistance of 40Cr steel

Closed double-point high-speed precision press is the core equipment of intelligent equipment production line of sheet metal forming. The uneven gap between ball head and ball bowl will cause serious noise pollution. The ball bowl is usually made of brass. In order to improve the friction wear performance and corrosion resistance of the ball head and ball bowl, the ball head base material 40Cr was nitrided, TiN coating and AlCrN coating are prepared on the nitride layer by Physical Vapor Deposition. The effects of different surface treatments on friction wear performance and corrosion resistance of 40Cr steel were analyzed by scanning electron microscope, electron microscope, X-ray diffractometer, microhardness tester, friction and wear tester and GAMRY ESA410 electrochemical workstation. The results show that nitriding can improve the hardness of 40Cr steel and friction wear performance, while nitriding combined with coating can obviously improve the hardness and friction wear performance. The wear mechanism of 40Cr steel and nitride layer is mainly abrasive wear and adhesive wear. The adhesion of TiN coating and AlCrN coating is 26 N and 23 N respectively. The wear mechanism of TiN coating and AlCrN coating is mainly adhesive wear. The highest corrosion potential and the lowest corrosion current density indicate that the AlCrN coating has the best corrosion resistance, followed by the TiN coating, and the nitride layer has lower corrosion resistance than coatings but is better than 40Cr steel.