摘要
以不同碳含量(0.01%C和0.14%C)的Fe-Ni-Al马氏体时效钢作为研究对象,通过固溶和等温时效试验,利用光学显微镜、场发射扫描电镜、场发射透射电镜研究了碳含量对等温时效过程中Fe-Ni-Al马氏体时效钢显微组织的影响,并利用维氏硬度计和电子万能试验机测试了等温时效过程中的硬度和拉伸性能变化规律。结果表明,经900℃固溶处理后,当碳含量由0.01%提升至0.14%时,马氏体组织相变驱动力增加使其形核率增加,同时碳含量的提升产生较多的未溶碳化物,对晶界起到钉扎效应,使试验钢中淬火马氏体宽度细化0.2μm。经500℃时效处理后,两种试验钢中的碳化物均为(Nb, Mo)C,碳含量的提升可以提高试验钢在时效过程中析出碳化物的形核率。当时效时间由1 h增加至4 h时,0.01%C钢和0.14%C钢中析出碳化物平均尺寸分别增加4.99和5.82 nm,且时效4 h后的0.14%C钢中形成了大量弥散分布的碳化物。碳含量的提升可使试验钢的硬度提高约18 HV10,抗拉强度提高177 MPa。
Solution and isothermal aging treatment were carried out to study the effects of different carbon contents(0.01%C and 0.14%C)on microstructure of Fe-Ni-Al maraging steel during isothermal aging observed by means optical microscope,field emission scanning electron microscope and field emission transmission electron microscope,and the changes of hardness and tensile properties of the tested steel during isothermal aging were tested by using Vickers hardness tester and electronic universal testing machine.The results show that after solution treatment at 900℃,the nucleation rate of martensite increases with the carbon content increasing from 0.01%to 0.14%due to the increase of the driving force of the phase transformation,and the pinning effect of more undissolved carbides on the grain boundaries is produced by the increase of carbon content,which refines the width of the quenched martensite by 0.2μm.After aging at 500℃,the carbides in both the two tested steels are(Nb,Mo)C,and the increase of carbon content can improve the nucleation rate of precipitated carbides during aging.When the aging time increases from 1 h to 4 h,the average size of precipitated carbides in 0.01%C steel and 0.14%C steel is increased by 4.99 nm and 5.82 nm,respectively,and a large number of dispersedly distributed carbides are formed in the 0.14%C steel after aging for 4 h.The increase in carbon content can improve the hardness of the tested steel by about 18 HV10 and the tensile strength by 177 MPa.
作者
周桐
邢磊
姚柯
张宇轩
李一鸣
王海燕
Zhou Tong;Xing Lei;Yao Ke;Zhang Yuxuan;Li Yiming;Wang Haiyan(School of Materials Science and Engineering,Inner Mongolia University of Science&Technology,Baotou Inner Mongolia 014010,China)
出处
《金属热处理》
北大核心
2025年第7期103-111,共9页
Heat Treatment of Metals
基金
国家自然科学基金(52161008,52361012)
中央引导地方科技发展基金(2022ZY0072)
内蒙古自治区直属高校基本科研业务费项目(2023QNJS006)
阳江市合金材料与五金刀剪重点产业人才振兴计划专项基金(RCZX2022020)。
