碳强化型超低碳钢组织性能及强化机理  

Microstructure,properties and strengthening mechanism of carbon-strengthened ultra-low carbon steel

作　　者：刘再旺 刘广会 曹荣华 杨利斌 LIU Zaiwang;LIU Guanghui;CAO Ronghua;YANG Libin(Research Institute of Technology,Shougang Group Co.,Ltd.,Beijing 100043,China;Beijing Key Laboratory of Green Recyclable Process for Iron and steel Production Technology,Beijing 100043,China;Technology Center,Shougang Jingtang United Iron and Steel Co.,Ltd.,Tangshan 063210,Hebei,China)

机构地区：[1]首钢集团有限公司技术研究院,北京100043 [2]绿色可循环钢铁流程北京市重点实验室,北京100043 [3]首钢京唐钢铁联合有限责任公司技术中心,河北唐山063210

出　　处：《中国冶金》2024年第4期138-144,共7页China Metallurgy

基　　金：河北省重大科技成果转化专项(22281001Z)。

摘　　要：为了探索碳含量对超低碳钢力学性能的影响,在实验室冶炼了3种碳质量分数分别为0.002%、0.005%、0.008%的超低碳钢,将其轧制成热轧板,并分析碳含量和热轧卷取温度对钢板的力学性能、显微组织和第二相析出的影响。结果表明,随着碳质量分数由0.002%增加至0.008%,钢的屈服强度、抗拉强度明显增加,断后伸长率降低;随着碳含量的升高,580℃卷取时的强度变化比730℃卷取时的更显著。试验钢晶粒尺寸由碳质量分数为0.002%、卷取温度为730℃时的22μm减小至碳质量分数为0.008%、卷取温度为580℃时的11μm,第二相TiC粒子平均尺寸半径由碳质量分数为0.002%、卷取温度为730℃的35 nm减小至碳质量分数为0.008%、卷取温度为580℃时的10 nm。在碳质量分数为0.008%、卷取温度为730℃时,钢板的屈服强度达到230 MPa以上,计算得出其细晶强化值为64.5 MPa、析出强化值为56.8 MPa。工业生产数据显示,碳质量分数为0.008%时,超低碳钢的力学性能水平可满足高强IF钢的标准要求。In order to find out the effect of carbon content on the mechanical properties of ultra-low carbon steel,three types of ultra-low carbon steel with carbon mass fraction of 0.002%,0.005%,and 0.008%were smelted in the laboratory,which were rolled as hot steel sheet.Mechanical properties,microstructure and second phase precipitation of the steel sheet were observed.The results show that,with the increase of carbon mass fraction from 0.002%to 0.008%,the yield strength and tensile strength of the steel significantly increase,while the elongation after fracture decreases.With the increase of carbon content,the strength change at 580℃coiling is more significant than that at 730℃coiling.The grain size of test steel decreases from 22μm at carbon mass fraction of 0.002%and coiling temperature of 730℃to 11μm at carbon mass fraction of 0.008%and coiling temperature of 580℃,and second phase TiC particles average size decreases from 35 nm at carbon mass fraction of 0.002%and coiling temperature of 730℃to 10 nm at carbon mass fraction of 0.008%and coiling temperature of 580℃.When the carbon mass fraction is 0.008%and the coiling temperature is 730℃,the yield strength of the steel sheet reaches more than 230 MPa,the calculated grain-refining strengthening value is 64.5 MPa and the precipitation strengthening value is 56.8 MPa.Industrial production data show that when the carbon mass fraction of the ultra-low carbon steel is 0.008%,the mechanical properties can meet the standard requirements of high-strength IF steel.

关 键 词：超低碳钢 卷取温度 细晶强化 析出强化 碳化钛 

分 类 号：TG142.31[一般工业技术—材料科学与工程]