珠光体片间距的热力学控制及其对钢力学性能的影响  

Thermodynamic control of pearlite lamellar sheet spacing and its effect on mechanical properties of steel

作　　者：莫文锋[1] Mo Wenfeng(School of Mechanical and Electrical Engineering,Liuzhou Vocational and Technical College,Liuzhou 545616,Guangxi,China)

机构地区：[1]柳州职业技术学院机电工程学院,广西柳州545616

出　　处：《钢铁钒钛》2021年第5期175-179,共5页Iron Steel Vanadium Titanium

基　　金：2020年度广西高校中青年教师基础能力提升项目(2020KY31012)。

摘　　要：利用实验室炼钢、轧制、热处理等手段获得了成分一致但珠光体片间距不同的两种材料,利用扫描电镜和万能试验机对比研究了珠光体片间距与力学性能之间的关系,得到以下结论:试验材料的珠光体片层间距的倒数S_(p)^(-1)(μm^(-1))与其珠光体转变过冷度△T(℃)满足线性关系S_(p)^(-1)=9.020 1+0.033 58△T,可知该材料进行550℃等温处理可获得理论上最细珠光体片间距(约61 nm)。随着极细珠光体片间距的细化,由105 nm降至72 nm时,材料强度上升的同时会出现塑性显著恶化,其极限变形应变值由0.18降至0.12,这与传统细晶强化理论不一致,其原因是细化的珠光体片层抑制了位错的自由运动。A pearlite steel was prepared via laboratory steelmaking,and then after rolling and heat treatment to obtain two different samples with different pearlite lamellar spacing.The mechanical properties and microstructures of the materials were observed by scanning electron microscopy and universal testing machine.Results show that the reciprocal S_(p)^(-1)(μm^(-1))of pearlite lamellae and transformation super cooling degree of pearlite△T(℃)satisfy the linear relationship of S_(p)^(-1)=9.0201+0.03358△T.This indicates that the theoretical minimum pearlite lamellae spacing(~61 nm)can be obtained by isothermal treatment at 550℃.With the thinning of the spacing between the very fine pearlite lamellar(from 105 to 72 nm),the strength increases but ductility will deteriorate significantly,and the ultimate deformation strain will decrease from 0.18 to 0.12.This result conflicts with the traditional grain refinement strengthening theory.The reason is that the refined pearlite lamellar restrains the free movement of dislocations.

关 键 词：高强钢 珠光体 片层间距 强度 塑性 电子背散射衍射 

分 类 号：TF76[冶金工程—钢铁冶金] TG142.1[一般工业技术—材料科学与工程]