铌含量对HR3C钢在高温时效过程中显微组织演变的影响  

Effect of Niobium Content on Microstructure Evolution of HR3C Steel During High Temperature Aging

作　　者：杨聪辉 曹铁山[1] 陈献刚 程从前[1] 赵杰[1] YANG Conghui;CAO Tieshan;CHEN Xiangang;CHENG Congqian;ZHAO Jie(School of Materials Science and Engineering,Dalian University of Technology,Dalian 116024,China;Inner Mongolia North Heavy Industries Group Co.,Ltd.,Baotou 014030,China)

机构地区：[1]大连理工大学材料科学与工程学院,大连116024 [2]内蒙古北方重工业集团有限公司,包头014030

出　　处：《机械工程材料》2023年第2期26-32,66,共8页Materials For Mechanical Engineering

基　　金：国家自然科学基金资助项目(51901035,U1610256)。

摘　　要：在HR3C钢化学成分的基础上调整铌元素的质量分数分别为0.5%,0.8%和1.1%,熔炼得到3种成分钢锭,再进行热轧、1200℃均匀化退火和固溶处理、750℃不同时间(0~2000 h)时效处理,研究了铌含量对试验钢显微组织、晶粒尺寸和硬度的影响。结果表明:增加铌含量将提高固溶态试验钢中未溶MX相的含量,减小晶粒尺寸;在750℃时效过程中,增加铌含量会促进σ相在晶界和晶内的析出和粗化,提高硬度;在时效2000 h时铌含量对晶界析出相的尺寸和分布影响不大,但对晶内析出相的尺寸和形态有所影响,铌质量分数1.1%试验钢中晶内析出相的数量相对较少且呈条状。On the basis of the chemical composition of HR3C steel,the mass fractions of niobium element were adjusted to 0.5%,0.8%and 1.1%,respectively.The ingot samples with the three components were obtained by melting,and then subjected to hot rolling,homogenization annealing at 1200℃,solid solution at 1200℃,and aging at 750℃for different times(0-2000 h).The effects of niobium content on the microstructure,grain size and hardness of the test steel were studied.The results show that increasing the niobium content could increase the content of undissolved MX phase in the solid solution test steel and reduce the grain size.During aging at 750℃,increasing the niobium content could promote the precipitation and coarsening ofσphase at grain boundaries and inside grains,and improve the hardness.When aging for 2000 h,the niobium content had little effect on the size and distribution of grain boundary precipitates,but had some influence on the size and shape of intragranular precipitates;the test steel containing 1.1wt%niobium had a relatively small number of strip-like intragranular precipitates.

关 键 词：HR3C钢 铌 Σ相 硬度 显微组织 高温时效 

分 类 号：TG142.13[一般工业技术—材料科学与工程]