弛豫工艺对耐候桥梁钢组织及性能的影响  

Influence of Relaxing Process on Microstructure and Mechanical Properties of Weather-proof Bridge Steel

作　　者：黄乐庆 王彦锋[1] 杨永达[1] 马长文[1] 狄国标[1] 韩承良 HUANG Leqing;WANG Yanfeng;YANG Yongda;MA Changwen;DI Guobiao;HAN Chengliang(Plate Technology Department,Shougang Research Institute of Technology,Beijing 100043,China;Beijing Engineering Research Center of Energy Steel,Beijing 100041,China;Qinghungdao Shouqin Metal Materials Co.,Ltd.,Qinghungdao Hebei 066326,China)

机构地区：[1]首钢技术研究院宽厚板所,北京100043 [2]北京市能源用钢工程技术研究中心,北京100041 [3]秦皇岛首秦金属材料有限公司,河北秦皇岛066326

出　　处：《上海金属》2019年第1期1-5,共5页Shanghai Metals

基　　金：国家重点研发计划(No.2017YFB0304800)

摘　　要：利用金相分析、力学性能测试、电子探针以及周浸加速腐蚀等方法,研究了轧后直接水冷、弛豫30、85及270 s对420 MPa级耐候桥梁钢显微组织、力学性能及耐候性能的影响。结果表明:随着弛豫时间的延长,试验钢板的组织类型由针状铁素体(AF)+粒状贝氏体(GB)逐渐转变为铁素体(F)+贝氏体(B),并进一步转变为铁素体(F)+珠光体(P);同时,试验钢板的屈服强度的下降速率明显大于抗拉强度的,屈强比由0. 88降低至0. 62;周浸试验结果表明:在弛豫过程中耐候性元素未发生明显的扩散,因而钢板的腐蚀速率波动不大。Influence of relaxing process,namely direct water cooling,relaxing for 30 s,85 s and 270 s,on the microstructure,mechanical properties and weathering resistance of 420 MPa grade weather-proof bridge steel after rolling was researched by means of metallographic analysis,mechanical property test,electron probe and cyclic dry-wet accelerated corrosion test.The results showed that with the extension of relaxation time,the microstructure of the test steel plate was gradually changed from acicular ferrite(AF)plus granular bainite(GB)to ferrite(F)plus bainite(B),and further transformed to ferrite(F)plus pearlite(P);moreover,the yield strength dropped faster than the tensile strength,thus the yielding-to-tensile ratio decreased from 0.88 to 0.62.The results of cyclic dry-wet accelerated corrosion test showed that there was no significant diffusion of the weather-proof elements during the relaxing,so the corrosion rate of the steel plate fluctuated a little.

关 键 词：弛豫时间 耐候桥梁钢 组织与性能 耐候性能 

分 类 号：TG142.1[一般工业技术—材料科学与工程] U446[金属学及工艺—金属材料]