终轧温度和卷取温度对Ti-V微合金钢组织及析出物的影响  

Effects of finishing and coiling temperatures on microstructure and precipitate of Ti-V micro-alloyed steel

作　　者：王丽 Wang Li(Guiyang Institute of Humanities and Technology,Architectural Engineering Institute,Guiyang,550000,China)

机构地区：[1]贵阳人文科技学院建筑工程学院,贵阳550000

出　　处：《材料与冶金学报》2024年第6期577-584,共8页Journal of Materials and Metallurgy

基　　金：贵阳人文科技学院2023年度科研基金项目(2023rwjs036)。

摘　　要：使用Gleeble-3800热机械模拟机对Ti-V微合金钢进行6道次压缩变形试验,在给定的始轧温度1 050℃、应变速率1 s-1及道次间歇时间10 s的条件下,研究不同终轧温度和卷取温度对其组织和析出物的影响.结果表明:当终轧温度从850℃降低至775℃时,铁素体晶粒尺寸从15.1μm减小至3.8μm;降低终轧温度具有细化铁素体晶粒尺寸的效果.Ti-V微合金钢在不同变形条件下均有析出现象,当终轧温度为800℃、卷取温度为550℃时,析出物颗粒尺寸既有粗大的,也有细小的,平均颗粒尺寸为34.6 nm,主要以弥散的分布形式存在,也有链状的分布形式,其形貌大部分为球形或椭圆形,小部分为立方形、矩形或不规则形.从热力学角度分析,析出物的形貌特征主要取决于界面能,当界面能起主导作用时,其形貌为球形;当析出物长到足够大,界面能不起主导作用时,其形貌则转变为立方形或矩形.此外,Ti-V微合金钢在不同的变形条件下都有较高的位错密度,这是因为析出物对位错的钉轧作用会让其他滑移系新位错源开动,出现多滑移现象,从而提高位错密度,产生位错强化.The Ti-V micro-alloyed steel was subjected to 6-pass compression deformation tests using a Gleeble-3800thermomechanical simulator.Under the given conditions of an initial rolling temperature of 1050℃,a strain rate of 1 s-1,and an inter-pass time of 10 s,the effects of finishing and coiling temperatures on the evolution of microstructures and the precipitation phase in Ti-V micro-alloyed steel have been studied.The result shows that when the finishing temperature reduces from 850℃to 775℃,the grain size of ferrite decreases from 15.1μm to 3.8μm.It is found that reducing the final rolling temperature has the effect of refining the ferrite grain size.The Ti-V micro-alloyed steel has precipitation phenomena under different conditions.When the finishing temperature is 800℃and the coiling temperature is 550℃,the precipitation phase has both coarse and small,with an average particle size of 34.6 nm.The precipitation phase mainly exists in the form of dispersed distribution and also in the form of chain distribution.Most of them are spherical or elliptical,and a small part is cubic,rectangular,or irregular.From the perspective of thermodynamics,the morphology of the precipitation phase depends mainly on the interfacial energy,when the interfacial energy plays a significant role,the morphology is spherical,when the precipitation phase grows up sufficiently,and the interfacial energy does not play a dominant role,the morphology changes to cubic or rectangular.In addition,the Ti-V micro-alloyed steel under different deformation conditions has relatively high dislocation density,This is because the pinning effect of the precipitation phase on dislocations can activate new dislocation sources in other slip systems,resulting in multiple slip phenomena,thereby increasing dislocation density,and resulting in dislocation strengthening.

关 键 词：Ti-V微合金钢 显微组织 析出物 控制轧制 

分 类 号：TF4[冶金工程—钢铁冶金] TG1[金属学及工艺—金属学]