冷轧压下率和退火工艺对合金钢50CrNiMoVNb再结晶的影响  

Influence of cold rolling reduction rate and annealing process on recrystallization of alloy steel 50CrNiMoVNb

作　　者：朱施利[1] Zhu Shili(Technology Center,Ningbo Iron&Steel Co.,Ltd.,Ningbo Zhejiang 315807,China)

机构地区：[1]宁波钢铁有限公司技术中心,浙江宁波315807

出　　处：《金属热处理》2024年第11期161-166,共6页Heat Treatment of Metals

基　　金：宁波市重大科技任务攻关项目(2022Z105)。

摘　　要：利用冷轧机对50CrNiMoVNb退火钢带进行冷轧,采用高温马弗炉对冷轧试样进行退火,并通过金相显微镜、显微硬度计研究冷轧压下率、退火温度和退火时间对再结晶的影响。结果表明,增加冷轧压下率能提高再结晶晶粒生长速度,压下率越大,再结晶后的晶粒越细小和均匀;800℃退火1 h试样平均晶粒尺寸从0%压下率的8.0μm减小到50%压下率的5.6μm。相同冷轧压下率的试样退火后空冷,随着退火温度的升高,硬度先降低后升高。提高退火温度和延长保温时间,再结晶度提升;冷轧压下率为30%时,800℃退火70 min完成再结晶。再结晶体积分数x、再结晶时间t_(R)、再结晶晶粒尺寸d与形核率N、线生长速度v和保温时间t之间的关系为:x(t)≈Nv^(3)t^(4)、t_(R)=^(4)√3/πNv^(3)、d=2^(4)√3v/πN。50CrNiMoVNb steel belts after annealing were cold rolled by using cold rolling mill,and the cold rolled specimens were annealed in high temperature muffle furnace.The effects of cold rolling reduction rate,annealing temperature and annealing time on recrystallization were studied by means of metallographic microscope and microhardness tester.The results show that the growth rate of recrystallized grains is increased with the increase of cold rolling reduction rate,and the greater the reduction rate,the finer and more uniform recrystallized grains.The average grain size of the steel annealed at 800℃for 1 h is reduced from 8.0μm at reduction rate of 0%to 5.6μm at reduction rate of50%.At the same cold rolling reduction rate,when the steel is air cooled after annealing,the hardness decreases first and then increases with the increase of annealing temperature.The degree of recrystallization completion is improved with annealing temperature increasing and holding time prolonging.The completion time of recrystallization is 70 min for the steel with the reduction rate of 30%at the annealing temperature of 800℃.The relationships between the volume fraction x,the recrystallization time t_(R),grain size d and the nucleation rate N,linear growth rate v,holding time t are x(t)≈Nv^(3)t^(4)、t_(R)=^(4)√3/πNv^(3)、d=2^(4)√3v/πN。,respectively.

关 键 词：冷轧压下率 退火温度 保温时间 合金钢50CrNiMoVNb 再结晶 

分 类 号：TG142.3[一般工业技术—材料科学与工程]