Abstract: During rolling steel AISI1008 for claw machine in rolling line of steel bar,the mixed crystal phenomenon occurs. The ferrite grain size rating at the edge, 1/2 radius and center of Φ50 mm rolled bar is respectively 3,8 and 8. Through metallographic and electron microscopic examination of round steel, the finite element simulation of finish rolling temperature and equivalent strain is carried out by using Deform software. It is found that the cause of coarse grain size at the edge of round steel is related to the low finish rolling temperature and the large equivalent strain during rolling. With improvement measures to increase the finish rolling temperature from 820°C to 880°C, ,the uniformity of section grain size of round steel is successfully improved.

Key words:  , Steel AISI1008, Mixed Crystal, Finishing Rolling Temperature, Equivalent Strain, Finite Element Simulation ,

摘要： 在棒材线轧制锻造爪机用AISI1008钢时,出现混晶现象,Φ50 mm棒材边缘铁素体晶粒度3级,1/2半径及心部铁素体晶粒度8级,通过对钢材进行金相组织及电镜检验,对轧制过程温度及等效应变利用Deform软件进行有限元模拟,发现造成圆钢边缘晶粒粗大的原因与终轧温度过低及轧制等效应变大且分布不均有关,将终轧温度由原820℃提高至880℃,成功改善了圆钢横截面混晶现象。

关键词: AISI1008钢, 混晶, 终轧温度, 等效应变, 有限元模拟