钒添加量对冷硬铸铁组织及耐磨性的影响

Effect of Vanadium Addition Amount on Microstructure and Wear Resistance of Chilled Cast Iron

采用金属型铸造制备了添加不同质量分数(0~2.0%)钒的冷硬铸铁,研究了钒含量对冷硬铸铁显微组织以及抗冲击磨粒磨损和摩擦磨损性能的影响。结果表明:随着钒质量分数的增加,冷硬铸铁的显微组织发生细化,碳化物分布更加均匀,碳化物由网状变为长条状,但当钒质量分数高于1.2%时碳化物长大聚集;随钒质量分数增加,冲击磨粒磨损试验后冷硬铸铁的磨损质量损失先下降后略微升高,当钒质量分数为1.2%时,抗冲击磨粒磨损性能最佳;添加质量分数0,1.2%钒的冷硬铸铁在1 J冲击功下的冲击磨粒磨损机理分别以微观切削和塑性疲劳为主;钒的添加降低了冷硬铸铁与45钢对磨时的摩擦因数,提高了冷硬铸铁的摩擦磨损性能;添加质量分数0,1.2%钒的冷硬铸铁在6.9 N载荷下的摩擦磨损机理分别为微观切削和疲劳磨损,9.8 N载荷下为磨粒磨损和疲劳磨损。

Chilled cast iron with different mass fractions(0-2.0%) of vanadium was prepared by metal mold casting. The effect of vanadium content on the microstructure, impuct abrasive wear resistance and frictional wear resistance of chilled cast iron was studied. The results show that with the increase of vanadium mass fraction, the microstructure of chilled cast iron was refined, the carbide distribution was more uniform, and the carbide changed from network to long strip. When the vanadium mass fraction was higher than 1.2%, the carbides were coarsened and aggregated. With the increase of vanadium mass fraction, the wear mass loss of chilled cast iron decreased first and then increasesd slightly after impact abrasive wear test, and the impact abrasive wear resistance was the best when vanadium mass fraction was 1.2%. The impact abrasive wear mechanism of chilled cast iron with mass fraction 0, 1.2% vanadium under 1 J impact energy was micro-cutting and plastic fatigue, respectively. The addition of vanadium improved the frictional and wear properties of chilled cast iron. The frictional wear mechanisms of chilled cast iron with 0, 1.2% mass fraction of vanadium under 9.8 N load were abrasive wear, fatigue wear, respectively, under 6.9 N load were micro-cutting and fatigue wear, respectively.