退火工艺对低成本980 MPa级冷轧双相钢组织和性能的影响  

Effect of annealing process on structure and properties of a low cost 980 MPa cold-rolled dual-phase steel

作　　者：刘鹏飞 关琳 刘建 陈宇 刘宏亮 Liu Pengei;Cuan Lin;Liu Jian;Chen Yu;Liu Hongliang(Benxi Steel Plate R&D Institute of Anshan Iron and Steel Group,Benxi Liaoning 117000,China;National and Local Joint Engineering Laboratory of Advanced Automotive Steel Development and Application Technology,Benxi Liaoning 117000,China;Ansteel Group,The Youth League Committee of Bengang Group Co.,Ltd.,Benxi Liaoning 117000,China)

机构地区：[1]本钢集团有限公司技术中心,辽宁本溪117000 [2]先进汽车用钢开发与应用技术国家地方联合工程实验室,辽宁本溪117000 [3]鞍钢集团本钢集团有限公司团委,辽宁本溪117000

出　　处：《金属热处理》2024年第3期122-127,共6页Heat Treatment of Metals

基　　金：辽宁“百千万人才工程”培养经费资助。

摘　　要：利用Vatron奥钢联热模拟试验机模拟一种980 MPa级冷轧双相钢连续退火过程,采用拉伸试验机、光学显微镜和扫描电镜研究连续退火工艺中均热温度、缓冷温度、过时效温度和带速对双相钢组织及力学性能的影响。结果表明,当均热温度为820、840和860℃时,随着均热温度的升高,组织中铁素体的比例不断下降,屈服强度不断提高。当均热温度提高到860℃时,组织中出现了一定量的贝氏体,抗拉强度达到了最低值1020 MPa;缓冷温度能够改变马氏体体积分数进而影响双相钢的性能;当过时效温度为250、270、290、310和330℃时,随着过时效温度的升高,马氏体发生软化的程度不断加剧,抗拉强度不断降低,断后伸长率不断升高,过时效温度升高到310℃以上时,马氏体分解加剧同时析出更多第二相,屈服强度先降低后升高。综合不同退火工艺下的冷轧双相钢的性能调控,最终确定均热温度840℃、缓冷温度680℃、过时效温度250℃和带速120 m/min为最佳的工艺参数,强塑积达到了最大值15.6 GPa·%。By simulating the continuous annealing process of a cold rolled 980 MPa dual-phase steel by a Vatron Voestalpine thermal simulator,the effect of soaking temperature,slow cooling temperature,overaging temperature and the strip speed in continuous annealing on microstructure and mechanical properties of the dual-phase steel was studied by means of tensile testing machine,optical microscope and scanning electron microscope.The results show that with the increase of the soaking temperature in the range of 820,840 and 860℃,the proportion of ferrite decreases and the yield strength increases.A certain amount of bainite appeares in the microstructure when the soaking temperature is increased to 860℃,which leads to the tensile strength reach the lowest value 1020 MPa.The slow cooling temperature can change the volume fraction of martensite and affect the mechanical properties of dual-phase steel.When the overaging temperature varies among 250,270,290,310 and 330℃,with the overaging temperature increases,the degree of softening of the martensile increases,the tensile strength decreases and the total elongation of the tested steel increases.With the increase of overaging temperature above 310℃,the decomposition of martensite is promoted,and at the same time the precipitations of second phases are increased and the yield strength decreases first and then increases.Comprehensively considering the mechanical properties control of the cold rolled dual-phase steel under different annealing processes,the optimal annealing parameters are selected as soaking temperature of 840℃,slow cooling temperature of 680℃,overaging temperature of 250℃and the strip speed of 120 m/min,under which the maximum value of the product of strength and elongation is 15.6 GPa·%.

关 键 词：双相钢 均热温度 缓冷温度 过时效温度 显微组织 力学性能 

分 类 号：TG142.1[一般工业技术—材料科学与工程]