终轧温度与终冷温度对440 MPa级船体钢组织与性能的影响  

Effect of Final Rolling Temperature and Cooling Temperatureon Microstructure and Properties of 440 MPa Hull Steel

作　　者：何有洪 杨成[3] 柴希阳[2] 师仲然 罗小兵[2] 刘静[1] HE Youhong;YANG Cheng;CHAI Xiyang;SHI Zhongran;LUO Xiaobing;LIU Jing(The State Key Laboratory of Refractories and Metallurgy,Wuhan University of Science and Technology,Wuhan 430081,China;Department of Structural Steels,Central Iron and Steel Research Institute,Beijing 100081,China;Technology Center of Angang Steel Co.,Ltd.,Anshan 114009,China)

机构地区：[1]武汉科技大学省部共建耐火材料与冶金国家重点试验室,湖北武汉430081 [2]钢铁研究总院工程用钢研究所,北京100081 [3]鞍钢股份有限公司技术中心,辽宁鞍山114009

出　　处：《热加工工艺》2024年第12期100-106,共7页Hot Working Technology

基　　金：国家自然科学基金项目(52201084)。

摘　　要：围绕船体钢强度升级与高效焊接的需求,设计了低C-Nb-V复合微合金化钢,研究了不同终轧温度与不同终冷温度下440 MPa级船体钢的组织与力学性能。结果表明:在未再结晶区终轧,随着终轧温度的降低,钢的晶粒得到细化,临界区轧制使钢中大小角度晶界密度大幅提高,同时带状珠光体逐渐退化,组织由铁素体+珠光体逐渐演变为准多边形铁素体+少量珠光体,在力学性能上体现为强度逐渐提高而-40℃冲击功保持稳定。随着终冷温度的降低,晶粒细化不明显,但是钢中大、小角度晶界密度显著提高,钢的组织由铁素体+珠光体转变为准多边形铁素体+珠光体,再转变为贝氏体+针状铁素体,在力学性能上体现为强度与-40℃冲击功的一并提高。Low C-Nb-V composite microalloyed steel was designed to meet the requirements of strength upgrading and efficient welding of hull steel.The microstructure and mechanical properties of 440 MPa steel at different final rolling temperatures(FRT)and different final cooling temperatures(FCT)were studied.The results show that during final rolling in the unrecrystallized zone,with the decrease of FRT,the grains are refined gradually,and rolling in critical zone greatly increases the density of low and high angular grain boundaries(LAGB,HAGB)in the steel.In the mean time,the pearlite band degrades gradually,and the microstructure change from ferrite+pearlite to qusi-polygonal ferrite+a little pearlite.The strength of the steel increases gradually while-40℃impact energy remains stable.With the decrease of FCT,the refinement of grains is inconspicuous,but the density of LAGB,HAGB increases significantly.The microstructure of the steels changes from ferrite+pearlite to qusi-polygonal ferrite+pearlite and then to bainite+acicular ferrite.Both strength and-40℃impact energy of the steel are improved.

关 键 词：440 MPa船体钢 终轧温度 终冷温度 

分 类 号：TG335[金属学及工艺—金属压力加工]