热轧后冷却速度和卷取温度对汽车用低合金高强钢板中析出物的影响  

Effect of Cooling Rate and Coiling Temperature after Hot-rolling on Precipitates in Low-alloy High-strength Steel for Automobile

作　　者：王畅[1,2] 于洋 王林[1,2] 张亮亮 李振[2] 陈瑾 WANG Chang;YU Yang;WANG Lin;ZHANG Liangliang;LI Zhen;CHEN Jin(Shougang Research Institute of Technology, Beijing 100043, China;Beijing Key Laboratory of Green Recyclable Process for Iron and Steel Production Technology, Beijing 100043, China;Qian’an Iron and Steel Company of Shougang Co., Ltd., Qian’an Hebei 064404, China)

机构地区：[1]首钢技术研究院,北京100043 [2]绿色可循环钢铁流程北京市重点实验室,北京100043 [3]首钢股份公司迁安钢铁公司,河北迁安064404

出　　处：《上海金属》2021年第1期50-54,共5页Shanghai Metals

摘　　要：采用Gleeble-3500热模拟试验机研究了层流冷却速度和卷取温度对汽车用低合金高强钢板热轧过程中析出行为的影响。结果表明:热轧过程中钢中析出物主要为多边形Nb(C,N)和细小NbC;随着热轧后层冷速度的增大,析出物尺寸减小、长大速度减慢,其密度从200个/μm2减少到了50个/μm2。试样热轧后层冷至400℃的卷取过程中,由于析出驱动力不足,析出物的数量骤减,其密度从250个/μm2减小到了25个/μm2。控制热轧过程中析出物的尺寸和数量并尽量减少含Nb析出物的数量,有利于连续退火后得到细小均匀的组织,产生细晶强化和析出强化的双重强化效果。Effect of laminar cooling rates and coiling temperatures after hot-rolling on precipitating behavior of low-alloy high-streng th steel plate for automobile was investigated by a Gleeble-3500 thermal simulation test machine.The results showed that phases precipitated during hot-rolling were predominantly polygonal Nb(C,N)and fine NbC,and as the laminar cooling rate after hot-rolling increased,the precipitates became finer and grew more slowly,with their number density decreasing from 200 perμm2 to 50 perμm2.The precipitates in the sample undergoing hot-rolling and laminar cooling to 400℃followed by coiling decreased drastically in amount,with their number density decreasing from 250 perμm2 to 25 perμm2,because of insufficient precipitation driving force.The control of both amount and size of the phases precipitated during hot-rolling and minimizing the amount of niobium-containing precipitates will help to obtain fine and uniform structure and to develop double strengthening effects of fine-grained strengthening and precipitation strengthening after continuous annealing.

关 键 词：低合金高强钢 第二相 析出 铌 层冷速度 卷取温度 

分 类 号：TG3[金属学及工艺—金属压力加工]