热轧钢材氧化铁皮的高温形变机理研究

摘要

The high-temperature deformation mechanism of oxide scale on low micro-alloy carbon steel was studied using a thermo-mechanieal simulator.The thickness,cross-sectional morphology,element distribution and grain structure of oxide scale were observed by electron probe microanalysis (EPMA) and electron backscatter diffraction (EBSD).The results indicated that the plasticity of oxide scale depended on temperature and degree of deformation.Furthermore,FeO layer was the primary region where plastic deformation distributed.This can be explained by the grain structure of FeO layer consisted of loose and larger columnar grains which was beneficial to the plastic deformation.Therefore,the oxide scale and steel substrate at high-temperature developed in equal proportion according to the plastic deformation mechanism of oxide scale,which revealed that the surface quality of hot-rolled steel could be improved by the hot-rolled process.%利用热力模拟实验机研究了低碳微舍金钢在热变形过程中钢材表面氧化铁皮的高温形变机理,并采用场发射电子探针和电子背散射衍射仪来表征氧化铁皮的厚度、截面形貌、元素分布和晶体结构.结果表明,在高温条件下钢材表面的氧化铁皮具有较好的塑性,氧化铁皮的变形特征与温度和变形量密切相关.此外,塑性变形的位置主要分布在FeO层,这主要是由于FeO的晶体结构为疏松粗大的柱状晶,利于其在高温下发生塑性变形.根据氧化铁皮塑性变形机制合理制定热轧工艺可以使钢材表面的氧化铁皮与钢基体等比例变形,从而达到改善热轧钢材表面质量的目的.