高加热速度下温度对45#钢再结晶和晶界特征的影响  

Effect of Temperature on Recrystallization and Grain Boundary Characteristics of 45#Steel at High Heating Rate

作　　者：贾智 王彤[1,2] 赵小龙 罗晓阳[3] 王慧芳[1,2] 张鹏飞 汪彦江 JIA Zhi;WANG Tong;ZHAO Xiao-long;LUO Xiao-yang;WANG Hui-fang;ZHANG Peng-fei;WANG Yan-jiang(School of Materials Science and Engineering,Lanzhou University of Technology,Lanzhou 730050,China;State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals,Lanzhou University of Technology,Lanzhou 730050,China;Carbon Steel Sheet Plant,Jiu Steel Group Hongxing Iron&Steel Co.,Ltd.,Gansu Jiayuguan 735100,China)

机构地区：[1]兰州理工大学材料科学与工程学院,兰州730050 [2]兰州理工大学省部共建有色金属先进加工与再利用国家重点实验室,兰州730050 [3]酒钢集团宏兴钢铁股份有限公司碳钢薄板厂,甘肃嘉峪关735100

出　　处：《精密成形工程》2023年第11期156-163,共8页Journal of Netshape Forming Engineering

基　　金：国家自然科学基金(52265049);甘肃省高等学校产业支撑计划(2022CYZC-26);兰州理工大学红柳优秀青年支持计划(CGZH001)。

摘　　要：目的针对45#钢的再结晶行为受退火工艺的影响较大这一问题,研究了2种加热速度下不同退火温度对45#钢再结晶行为、再结晶形核长大机制以及晶界特征分布的影响规律。方法采用箱式电阻炉模拟罩式退火实验,分别以2℃/s和0.08℃/s的加热速度将试样加热到不同温度(660℃、720℃)并保温30min,利用电子背散射衍射(EBSD)研究退火后45#钢的再结晶行为和晶界特征。结果与0.08℃/s加热速度相比,当加热速度为2℃/s时,试样的晶粒细小,再结晶温度较高。在高加热速度下,随着退火温度的升高,再结晶体积分数增大,一些小角度晶界转变为大角度晶界,促进了再结晶过程。再结晶晶粒通过亚晶合并形核并呈等轴状分布,亚晶粒通过相互吞并的方式生长,导致亚晶粒减少,几何必要位错密度增大。在2种加热速度下,720℃时(Σ9+Σ27)/Σ3的比值大于660℃时的比值,且在720℃下低ΣCSL晶界更高,更有利于45#钢中晶界团簇形成,晶界特征分布更优。结论与慢速加热相比,在高加热速度下退火会提高生产率,改善材料的微观结构,这主要通过晶粒细化来实现。The work aims to study the effect of different annealing temperature under two heating rates on the recrystallization behavior,recrystallization nucleation and growth mechanisms,and grain boundary characteristic distribution of 45#steel,so as to solve the problem that the recrystallization behavior of 45#steel is greatly influenced by the annealing process.The specimens were heated to different temperature(660℃ and 720℃)at 2℃/s and 0.08℃/s for 30℃ min by simulated hood annealing experiments in a box-type resistance furnace and the recrystallization behavior and grain boundary characteristics of the annealed 45#steel were investigated by the electron backscatter diffraction(EBSD)method.Compared to the heating rate of 0.08℃/s,the grain size of the specimenwas fine and the recrystallization temperature was increased when the heating rate was 2℃/s.At a high heating rate,with the increase of anneal ing temperature,the recrystallization volume fraction increased and some small-angle grain boundaries transformed into large-angle grain boundaries,thereby promoting the recrystallization process.Recrystallized grains nucleated and grew through the merging of subgrains,exhibiting an equiaxed distribution.Subgrains grew by mutual engulfment,leading to a reduction in subgrains and an increase in geometrically necessary dislocation density.At two heating rates,the ratio of(Σ9+Σ27)/Σ3 at 720℃ was higher than that at 660℃,and the grain boun dary at lowΣCSL is higher at 720℃,which was more conducive to the formation of grain boundary clusters and better grain boundary characteristic distribution in 45#steel.Therefore,compared with that at slow heating rate,the annealing at high heating rate can increase productivity and improve the microstructure of materials by grain refinement.

关 键 词：高加热速度 退火温度 45#钢 再结晶 晶界特征 

分 类 号：TG161[金属学及工艺—热处理]