摘要
利用膨胀法在Gleeble-3500热模拟试验机上测定了HRB400E抗震螺纹钢的静态连续冷却转变(CCT)曲线,采用光学显微镜OM、扫描电镜SEM和显微维氏硬度仪观察和测定了不同冷却速度下钢的显微组织和硬度,分析了冷却速度对该钢相变组织与性能的影响。结果表明,当冷速在3℃/s以下时,试验钢中组织为铁素体和珠光体,随着冷速的提高,试验钢中珠光体含量逐渐提高,片层间距不断减小;当冷速为4~10℃/s时,试验钢中开始出现贝氏体组织;当冷速>10℃/s时,试验钢开始发生马氏体相变;并且随着冷速的提高,试验钢的硬度逐渐提高。冷却速度为2~3℃/s范围内,试验钢中珠光体含量、片层间距和力学性能均满足GB/T 1499.2—2018中规定,其结果与现场生产性能检验结果相符。在冷速为3℃/s生产的φ8 mm盘螺成品试样的珠光体含量和片层间距分别为47%和0.184μm,下屈服强度R_(eL)、抗拉强度R_(m)、强屈比R_(m)/R_(eL)、屈标比R_(eL)/R_(eL)^(s)、断后伸长率A、最大力总伸长率A_(gt)分别为440 MPa、569 MPa、1.29、1.10、27.2%和17.8%。
The static continuous cooling transformation(CCT)experiments for anti-seismic rebar steel HRB400 E were conducted on Gleeble-3500 thermal simulation test machine by expansion method,The microstructure and hardness of the steel under different cooling rates were observed and measured by optical microscope(OM),scanning electron microscope(SEM)and micro-Vickers hardness tester,and the effect of cooling rate on the transformation structure and properties of the steel was analyzed.The results show that when the cooling rate is below 3℃/s,the microstructure of the tested steel is ferrite and pearlite.With the increase of cooling rate,the pearlite content in the tested steel increases gradually and the lamellar spacing decreases.Bainite appears in the tested steel when the cooling rate is 4-10℃/s.When the cooling rate is higher than 10℃/s,the tested steel begins to undergo martensitic transformation.With the increase of cooling rate,the hardness of the tested steel increases gradually.When the cooling rate is within the range of 2-3℃/s,the pearlite content,lamellar spacing and mechanical properties of the tested steel meet the technical requirements of the national standard GB/T 1499.2—2018.The experimental results are in good agreement with the mechanical properties of industrial products,in which,the pearlite content and lamellar spacing of the finished specimen ofφ8 mm rebar at the cooling rate of 3℃/s are 47%and 0.184μm respectively,and yield strength R_(eL),tensile strength R_(m),ratio of R_(m)/R_(eL),ratio of R_(eL)/R_(eL)^(s),fracture total elongation A and total elongation at maximum force A_(gt) are 440 MPa,569 MPa,1.29,1.10,27.2%and 17.8%,respectively.
作者
骆艳萍
汪家晗
李沐泽
张云祥
周建勋
赵志恒
Luo Yanping;Wang Jiahan;Li Muze;Zhang Yunxiang;Zhou Jianxun;Zhao Zhiheng(WISDRI Engineering&Research Incorporation Limited,Wuhan Hubei 430223,China;Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education,Wuhan University of Science and Technology,Wuhan Hubei 430081,China;Wugang Group Kunming Iron and Steel Co.,Ltd.,Anning Yunnan 650302,China)
出处
《金属热处理》
CAS
CSCD
北大核心
2022年第9期188-193,共6页
Heat Treatment of Metals
基金
国家自然科学基金(51774219)。
