Effects of Tempering Temperature on Microstructure and Friction and Wear Properties of 20CrMnTi Carburized Quenching Steel
In order to study the effects of tempering temperature on the microstructure and friction wear properties of 20CrMnTi carburized steel,20CrMnTi carburized steel was treated with different tempering temperatures(160 ℃-350 ℃).Then,the microstructure and hardness were characterized by using the scanning electron microscope,Rockwell hardness tester.Also,the friction and wear properties of different samples were investigated by using the optical microscope and the friction and wear testing machine.The results show that when the tempering temperature is 160 ℃-210 ℃,the surface microstructure of the sample is mainly martensite,and the martensite peel off and slides as hard particles on the surface,the wear mechanism is mainly abrasive wear.When the tempering temperature is 250 ℃.The surface microstructure of the sample is mainly composed of martensite,bainite,residual austenite and carburite,the material has good strong and toughness combination,it's wear rate is minimum of 2.702 ×10-8 mm3/(N m),and the wear mechanism is slight abrasive wear.When the tempering temperature is 300 ℃ and 350 ℃,the surface microstructure of the sample is mainly bainite.The toughness of the material is imporoved,and the surface hardness is greatly reduced,resulting in the increase of material wear.The tempering temperature of 20CrMnTi carburized quenching steel should be controlled slightly above Ms critical temperature,the phase microstructure of martenite+bainite+residual austenite+carburite can be obtained,at this time,the sample has the best wear resistance.
carburized quenching steeltemperingfriction and wearmicrostructure