退火工艺对新型DH钢显微组织和力学性能的影响  

Effect of Annealing Process on Microstructure and Mechanical Properties of a New Type of DH Steel

作　　者：王保磊 王俊峰 王华[1] 何燕霖[1] 李麟[1] WANG Baolei;WANG Junfeng;WANG Hua;HE Yanlin;LI Lin(School of Materials Science and Engineering,Shanghai University,Shanghai 200444,China;Central Research Institute,Baoshan Iron&Steel Co.,Ltd.,Shanghai 201900,China)

机构地区：[1]上海大学材料科学与工程学院,上海200444 [2]宝山钢铁股份有限公司中央研究院,上海201900

出　　处：《上海金属》2022年第6期48-54,共7页Shanghai Metals

摘　　要：对一种含0.17%C、0.15%Si、2.44%Mn、0.04%Cr、0.05%Nb和0.18%Al(质量分数)的新型DH钢进行了温度为780~840℃的模拟连续退火。采用扫描电子显微镜、透射电子显微镜、X射线衍射仪及拉伸试验等检测了钢的显微组织和力学性能。结果表明:随着退火温度的升高,钢的抗拉强度先降低后升高,断后伸长率先升高后降低;810℃退火的钢断后伸长率最高为16%,断后伸长率的变化与钢变形时残留奥氏体产生的TRIP效应密切相关;随着在贝氏体转变区持续时间的延长,钢的抗拉强度和屈服强度略微下降,断后伸长率先升高后降低,在贝氏体转变区持续90 s的钢强塑积最高,抗拉强度和断后伸长率相应为1001 MPa和17.9%。A type of DH steel,containing 0.17%C,0.15%Si,2.44%Mn,0.04%Cr,0.05%Nb and 0.18%Al by mass,was subjected to simulated continuous annealing at 780 to 840℃,and then was tested for microstructure and mechanical properties by scanning electron microscope,transmission electron microscope,X-ray diffractometer and tensile test.The results showed that(a)as the annealing temperature increased,the tensile strength of the steel decreased at first and then increased,and its elongation increased at first and then decreased;(b)the steel annealed at 810℃exhibited as maximum elongation as 16%,and the change in elongation was closely related to TRIP effect arising from retained austenite in the steel during deformation;(c)with the extension of duration in bainite transformation range,both the tensile strength and yield strength of the steel decreased slightly,its elongation increased at first and then decreased,and the steel held in bainite transformation range for 90 s provided the highest product of strength and plasticity,the tensile strength and the elongation being correspondingly 1001 MPa and 17.9%.

关 键 词：DH钢 显微组织 力学性能 残留奥氏体 TRIP效应 

分 类 号：TG156.21[金属学及工艺—热处理]