硅含量对两相区调质处理的新型船用低温钢摩擦磨损性能的影响

Effect of Silicon Content on the Friction and Wear Properties of the Novel Low Temperature Steel After Two-Phase Zone Quenching and Tempering Treatment

为了提高低温船舶用钢的低温磨擦磨损性能,设计并制备了4种新型不同Si含量(0.3%、0.6%、0.9%和1.2%)并采用两相区调质处理的船用低温高强钢试样。通过在不同温度下的干滑动摩擦磨损试验,配合力学性能测试以及白光干涉仪、扫描电子显微镜、金相显微镜等微观分析技术,研究并分析了新型船用低温钢的摩擦磨损性能。结果显示:在恒定低载荷(20 N)和恒定低滑动速率(10 mm/s)条件下,该新型船用钢板的磨痕表面硬度明显高于磨损前,摩擦机理以黏着磨损、疲劳磨损为主,部分区域发生氧化磨损,磨屑被挤压产生加工硬化层。其中,Si含量为1.2%的船用低温钢在20℃和-10℃下均表现出优异的摩擦磨损性能,平均摩擦系数分别为0.41(20℃)、0.38(-10℃);磨损量分别为1.695×10-5m3(20℃)、2.097×10-5m3(-10℃)。随着硅含量的上升,使得经过两相区调质热处理的船用低温钢金相组织不同程度细化,并且使得固溶强化不断加强,磨损量降低,钢材在低温条件下的耐磨性有所提高。

In order to improve the wear resistance of low-temperature marine steels,four types of novel low temperature marine steels with different silicon contents(0.3%,0.6%,0.9%,1.2%)were designed and fabricated,followed by the two-phase zone quenching and tempering process.The friction and wear properties of the as-obtained steels were studied by combined techniques of dry sliding friction tests under different temperatures,mechanical tests,white light interferometry,scanning electron microscopy and metallurgical microscope.Results showed that under a low constant load of 20 N and a low constant low sliding rate of 10 mm/s,the surface hardness of novel marine steels after wear test was higher than that before wear test.The friction mechanisms mainly belonged to adhesion wear and fatigue wear,and oxidation wear occurred at some regions.Furthermore,a working hardening layer was formed on the surface of the steels due to the extrusion of the wear debris.Among the four tested steels,the one with a silicon content of 1.2%possessed the best wear resistance at 20℃and-10℃,with the average friction coefficient of 0.41(20℃)and 0.38(-10℃),respectively.Meanwhile,the above steel also demonstrated the lowest wear weight losses of 1.695×10-5 m3 at 20℃and 2.097×10-5 m3 at-10℃.With the increase of silicon content,the structure of low temperature marine steel after two-phase quenching and tempering was refined in different degrees,which enhanced the solid solution strengthening and reduced the abrasion loss,and therefore the wear resistance of obtained steels at low temperature was improved.