冷却速度和回火温度对高强度低合金钢组织与力学性能的影响  

EFFECT OF COOLING RATE AND TEMPERING TEMPERATURE ON MICROSTRUCTURE AND MECHANICAL PROPERTIES OF HIGH STRENGTH LOW ALLOY STEEL

作　　者：孙浩源 唐广波[2] 刘善喜[3] Sun Haoyuan;Tang Guangbo;Liu Shanxi(Long Product Department of HBIS Group Tangsteel Company,Tangshan 063016,Hebei;Institute of Structural Materials,Iron and Steel Research Institute,Beijing 100081)

机构地区：[1]河钢集团唐钢公司长材部技术室,河北唐山063016 [2]钢铁研究总院结构材料研究所,北京100081 [3]河钢集团唐钢公司长材部,河北唐山063016

出　　处：《河北冶金》2023年第1期69-73,共5页Hebei Metallurgy

摘　　要：在Formastor-FII全自动膨胀仪上,测定了试验钢在不同冷却速度下膨胀量与温度的关系,测定了不同冷速下相转变后的显微组织和显微硬度;并对生产试验中不同回火温度下的显微组织及力学性能进行了分析。研究结果表明:试验钢冷却速度大于0.826℃/s时,室温组织全部为贝氏体;当冷却速度为0.278~0.139℃/s时,室温组织为马氏体+贝氏体;当冷却速度为0.139~0.056℃/s时,室温组织为贝氏体+极少量马氏体;当冷却速度小于0.056℃/s时,室温组织全部为贝氏体。随着冷却速度的增加,转变产物硬度逐渐增大。当冷却速度达到16.52℃/s以上时,试验钢在250℃回火后抗拉、屈服强度最高,可达到1900 MPa、1600 MPa左右,且具有良好的塑性,断面收缩率约为50%,伸长率约为13%。In the Formastor-FII automatic dilatometer,the relationship between the expansion amount and temperature of test steel at different cooling rates was measured,and the microstructure and microhardness of phase transition at different cooling rates were measured.The microstructure and mechanical properties at different tempering temperatures were analyzed.The results show that when the cooling rate of the test steel is greater than 0.826℃/s,the microstructure at room temperature is all martensite.When the cooling rate is 0.278~0.139℃/s,the microstructure is martensite+bainite at room temperature.When the cooling rate is 0.139~0.056℃/s,the microstructure is bainite+very small amount of martensite at room temperature.When the cooling rate is less than 0.056℃/s,all the tissues are martensite at room temperature.With the increase of cooling rate,the hardness of transition products increases gradually.When the cooling rate is above 16.52℃/s,the tensile strength and yield strength of the test steel after tempering at 250℃ can reach about 1900 MPa,1600 MPa,and has good plasticity,section shrinkage is about 50%,elongation is about 13%.

关 键 词：高强度低合金钢 冷却速度 显微组织 显微硬度 屈服强度 抗拉强度 

分 类 号：TG142.1[一般工业技术—材料科学与工程]