摘要
针对锥形磨浆机磨片的工作条件和失效分析,设计制备了一种低碳马氏体不锈钢Fe-0.04C-15Cr-3Ni-0.5Mo-0.1Nb。采用光学显微镜、扫描电子显微镜以及硬度、冲击和摩损试验等方法研究了热处理工艺对试验钢显微组织和性能的影响。结果表明,试验钢在940~1100℃之间加热保温1 h后空冷淬火,显微组织为板条马氏体和均匀分布的细小颗粒状含Nb的MC型碳化物,随加热温度的升高原始奥氏体晶粒逐渐长大,MC型碳化物颗粒减少,硬度在1020℃达到最大值45.2 HRC;经1020℃淬火550~750℃之间回火后,随回火温度的升高,在原奥氏体晶界和板条界析出M23C6型碳化物,硬度先减小后增大,韧性先增大后减小,700℃回火时,冲击吸收功达到最大值102.8 J,硬度达到最小值33 HRC,750℃回火时,由于开始形成奥氏体和M23C6型碳化物的溶解,回火后的空冷过程中奥氏体又形成马氏体,使硬度升高,冲击吸收功降低,在550~700℃之间回火,试验钢的耐磨性随回火温度的升高而降低。
Base on working conditions and failure analysis of conical refiner disc plate,a Fe-0. 04C-15Cr-3Ni-0. 5Mo-0. 1Nb low-carbon martensitic stainless steel was designed and prepared by induction melting. Effect of heat treatment on microstructure and properties of the steel was investigated by means of optical microscopy,scanning electron microscopy,hardness,impact and wear tests. The results show that the microstructure of the tested steel after quenching at 940-1100 ℃ is mainly consisted of lath martensite and fine MC-type carbides containing Nb uniformly distributed in the matrix. With the increasing of quenching temperature,the prior austenite grain size grows and the number density of MC-type carbides reduces gradually. The maximum hardness value of 45. 2 HRC is obtained for the steel quenched at 1020 ℃. Tempered between 550-750 ℃ after quenching at 1020 ℃,M23C6-type carbides precipitate at the prior austenite grain boundaries and lath boundaries. With the increasing of tempering temperature,the hardness is first decreased and then increased,the impact absorbed energy is first increased and then decreased. The maximum impact absorbed energy of 102. 8 J and the minimum hardness of 33 HRC value are obtained for the steel tempered at 700 ℃. Because of the formation of austenite and dissolution of M23C6 carbides during tempering at 750 ℃ and martensite formation during the air cooling after tempering,the hardness is increased and impact energy is reduced. Between 550-700 ℃,the wear resistance of the steel is decreased with the increasing of tempering temperature.
出处
《材料热处理学报》
EI
CAS
CSCD
北大核心
2015年第6期138-143,共6页
Transactions of Materials and Heat Treatment
基金
山东省自然科学基金(ZR2013EMM005)
关键词
低碳马氏体不锈钢
淬火+回火
显微组织
性能
low-carbon martensitic stainless steel
quenching and tempering
microstructure
property
