42CrMo4钢棒材的调质处理  

Quenching and Tempering of 42CrMo4 Steel Bar

作　　者：郑挺 史文[1,2,3] 张青 鲍新城 蒋振 顾晓文 ZHENG Ting;SHI Wen;ZHANG Qing;BAO Xincheng;JIANG Zhen;GU Xiaowen(School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China;State Key Laboratory of Advanced Special Steel, Shanghai 200444, China;Shanghai Key Laboratory of Advanced Ferrometallurgy, Shanghai 200444, China;Jiangsu Tongheng Hi- tech Metals Co.,Ltd., Nanjing Jiangsu 210035, China;Shanghai University Heat- treatment Co., Ltd., Shanghai 201822, China)

机构地区：[1]上海大学材料科学与工程学院,上海200444 [2]省部共建高品质特殊钢冶金与制备国家重点实验室,上海200444 [3]上海市钢铁冶金新技术开发应用重点实验室,上海200444 [4]江苏南钢通恒特材科技有限公司,江苏南京210035 [5]上海上大热处理有限公司,上海201822

出　　处：《上海金属》2021年第6期38-46,共9页Shanghai Metals

摘　　要：分别采用中频感应加热设备和网带炉对直径28和40 mm、长500 mm的42CrMo4钢棒材进行了调质处理:920~940℃加热250~400 s PAG水溶液淬火、600~620℃回火空冷和870℃加热100 min油淬、540℃回火水冷。并采用Deform软件模拟了棒材的感应加热速率。调质后检测了棒材的外观质量、显微组织、自表面至中心的硬度分布、力学性能以及冲击试样的断口形貌。结果表明:网带炉调质的棒材表面氧化严重,并有较轻微的脱碳;两种设备调质的棒材截面硬度均为35~38 HRC,显微组织为回火索氏体和极少量的铁素体;中频感应加热棒材至奥氏体化温度后的加热速率约为2℃/s,与网带炉的加热速率相近;两种设备调质的棒材的力学性能相近,抗拉强度为1100~1200 MPa,屈服强度为1000~1100 MPa,断后伸长率为13%~17%,断面收缩率为54%~60%,低温冲击吸收能量为60~80 J。Using a medium-frequency induction heating apparatus and a mesh belt furnace respectively,42CrMo4 steel bars 28 and 40 mm in diameter by 500 mm long were quenched and tempered as follows:heating at 920 to 940℃for 250 to 400 s and quenching in PAG aqueous solution,followed by tempering at 600 to 620℃and cooling in air,and heating at 870℃for 100 min and oil-quenching,followed by tempering at 540℃and cooling in water.The induction heating rates of the bars were simulated by Deform software.After being quenched and tempered,the bars were tested for appearance quality,microstructure,and variation in hardness from surface to center,mechanical properties,and fracture pattern of impact sample.The results showed that(a)the bar quenched and tempered in the mesh belt furnace was seriously oxidized,and exhibited a slight decarburization;(b)the bars quenched and tempered by these two apparatuses all had hardness ranging from 35 to 38 HRC in their cross-section and microstructure consisting of tempered sorbite and very small amount of ferrite;(c)rate of medium-frequency induction heating after reaching a temperature at which the bar has been austenitized was similar to one of heating the bar in the mesh belt furnace,being about 2℃/s;and(d)the bars quenched and tempered by these two apparatuses possessed similar mechanical properties such as tensile strength of 1100 to 1200 MPa,yield strength of 1000 to 1100 MPa,elongation of 13%to 17%,reduction of area of 54%to 60%,and low-temperature impact absorption energy of 60 to 80 J.

关 键 词：42CrMo4钢棒材 调质 中频感应加热 网带炉 数值模拟 

分 类 号：TG161[金属学及工艺—热处理]