回火时间对含0.01%B耐热钢中含B碳化物析出行为和力学性能的影响  

Effect of tempering time on precipitation behavior of B-containing carbides and mechanical properties of heat-resistant steel with 0.01%B

作　　者：韦英东 马煜林 匡成阳 宋楚 王润泽 张志辉 王子富 Wei Yingdong;Ma Yulin;Kuang Chengyang;Song Chu;Wang Runze;Zhang Zhihui;Wang Zifu(School of Mechanical Engineering,Shenyang University,Shenyang Liaoning 110044,China)

机构地区：[1]沈阳大学机械工程学院,沈阳辽宁110044

出　　处：《金属热处理》2024年第11期132-137,共6页Heat Treatment of Metals

基　　金：国家级大学生创新创业训练项目(202311035034);中国博士后科学基金面上项目(2019M661122)。

摘　　要：为了揭示含B碳化物在回火过程中的析出行为及其对耐热钢力学性能的影响,利用光学显微镜和扫描电镜观察了硼含量为0.01%的耐热钢经950℃等温淬火+700℃回火不同时间(10、30、60、90、120和150 min)后的含B碳化物形态和分布情况,并使用布氏硬度计和室温拉伸试验机研究了含B碳化物的析出行为对试验钢硬度和拉伸性能的影响规律。结果表明,随着回火时间的增加,试验钢基体均为板条状回火马氏体,含B碳化物尺寸逐渐长大,形状由块状逐渐变为长条大块团聚状。随着回火时间的延长,试验钢的硬度呈先下降后上升最后下降的趋势,而抗拉强度和屈服强度呈先增加后降低趋势。当回火时间≥30 min时,试验钢拉伸断口为带韧窝的韧性断裂。其中,700℃回火60 min时试验钢的强度最优,抗拉强度和屈服强度分别为931 MPa和817 MPa。In order to reveal the precipitation behavior of B-containing carbides during tempering and its effect on the mechanical properties of heat-resistant steel,the morphology and distribution of B-containing carbides in a heat-resistant steel with boron content of 0.01%isothermally quenched at 950℃and tempered at 700℃for different time(10,30,60,90,120 and 150 min)were observed by means of optical microscope and scanning electron microscope.And the effect of precipitation behavior of B-containing carbides on Brinell hardness and tensile properties of the tested steel was studied by Brinell hardness test and room temperature tensile test.The results show that with the increase of tempering time,the matrix of the tested steel is lath tempered martensite,while the B-containing carbides grow in size gradually,with the shape changing from blocky to long blocky clustered.With the increase of tempering time,the hardness decreases first,then increases and finally decreases,while the tensile strength and yield strength increase first and then decrease.When the tempering time is≥30 min,the tensile fracture of the tested steel is ductile fracture with dimples,and the strengths of the tested steel are the best when tempering at 700℃for 60 min,with the tensile strength and yield strength of 931 MPa and 817 MPa,respectively.

关 键 词：耐热钢 回火时间 含B碳化物 力学性能 

分 类 号：TG161[金属学及工艺—热处理]