稀土复合变质处理对改进型无限冷硬铸铁轧辊组织与性能的影响

Effect of RE Compound Modification Treatment on Microstructures and Properties of Modified Infinite Chilled Cast Iron Roll

以改进型无限冷硬铸铁为研究对象,采用光学显微镜、扫描电镜(SEM)、X射线衍射仪(XRD)、冲击试验机、硬度机等分析测试手段,研究了RE复合变质剂对改进型无限冷硬铸铁组织和力学性能的影响。实验结果表明,RE复合变质处理改善了改进型无限冷硬铸铁的铸态组织,细化了晶粒,消除了树枝状晶,减少了莱氏体形态的碳化物数量,使连续网状碳化物转变为不连续的网状、孤岛状和鱼骨状碳化物,碳化物的尖角明显钝化;变质无限冷硬铸铁的硬度达到56HRC,冲击韧度达到4.6 J/cm2,比未变质的无限冷硬铸铁分别提高了7.7%和31.4%。

In this paper, modified infinite chilled cast iron was designed. Effect of RE compound modification on microstructures and mechanical properties of modified infinite chilled cast iron roll was studied by optical microscopy, scanning electron microscopy （SEM）, X -ray diffractometer （XRD）, impact testing machine and hardness tester. The results show that RE compound modification ameliorated the cast organization of improved infinite chilled cast iron, refined grain, eliminated dendrite, reduced the amount of ledeburite form carbide, changed continuous network carbide into discontinuous network, island shape and herringbone shape carbide, sharp corner of carbide was deactivated; the hardness of modified infinite chilled cast iron reached 56HRC, its impact toughness reached 4.6 J/cm^2, increased 7.7% and 31.4% compared with unmodified infinite chilled cast iron.