退火软化对高强度钢300M组织及硬度的影响  

Effect of annealing soften on microstructure and hardness of high strength steel 300M

作　　者：王洪利 吴铖川 杜思敏 李源[2,3] 罗祥华 叶文冰[2,3] Wang Hongi;Wu Chenghuan;Du Simin;Li Yuan;Luo Xianghua;Ye Wenbing(Chengdu Advanced Metal Materials Industrial Technolgy Research Instiute Co.,Ltd.,Chengdu Sichuan 610300,China;Science and Technology Department,Changcheng Special Steel Company of Pangang Group,Jiangyou Sichuan,621701,China;State Key Laboratory of Metal Material for Marine Equipment and Application,Anshan Liaoning 1409,China)

机构地区：[1]成都先进金属材料产业技术研究院有限公司特钢技术研究所,四川成都610300 [2]攀钢集团江油长城特殊钢有限公司科技部,四川江油621701 [3]海洋装备用金属材料及其应用国家重点实验室,辽宁鞍山114009

出　　处：《金属热处理》2021年第3期100-103,共4页Heat Treatment of Metals

摘　　要：为提高300M钢的后续切削性能,拓宽300M钢的应用领域,研究了退火软化工艺对300M高强度钢显微组织及硬度的影响。结果表明,300M钢在Ac_(1)以下(730℃)退火,显微组织由马氏体转变为回火索氏体,碳化物呈球状或颗粒状;在两相区(780℃)退火,显微组织为珠光体+先共析铁素体,碳化物呈球状或短棒状;在Ac_(3)以上(860℃)退火,显微组织转变为珠光体+先共析铁素体,碳化物呈长薄片状。退火冷速对300M钢软化影响显著,冷速缓慢才能使碳化物充分析出并球化,硬度显著降低。300M钢两相区等温+缓慢冷却退火工艺下有更显著的软化效应,硬度可控制在240 HBW以下。In order to improve the subsequent machinability of 300 M steel and widen the application field,the effect of annealing process on microstructure and hardness of 300 M steel was studied.The results show that annealing at 730℃below Ac1,the microstructure of 300 M steel is transformed from martensite to tempered sorbite with spherical or granular carbides.The microstructure is consisting of ferrite,lamellar pearlite with partial spheroid carbides when annealing at 780℃in intercritical phase region.Annealing at 860℃above Ac3,The microstructure is ferrite and lamellar pearlite with long thin sheet carbide.The cooling rate has a significant effect on the hardness of 300 M steel,the slow cooling rate results in the spheroidization of carbides and the decrease of hardness.The softening effect of 300 M steel is more obvious annealing at intercritical phase region with low cooling rate,and the hardness can be less than 240 HBW.

关 键 词：300M钢 退火 显微组织 硬度 

分 类 号：TG156.2[金属学及工艺—热处理]