高硅无取向电工钢的高温氧化行为

High temperature oxidation behavior of high silicon non oriented electrical steel

采用对比实验研究了不同温度下的高硅无取向电工钢的氧化行为,利用场发射扫描电子显微镜及其EDS功能观察了经不同温度(1030~1240℃)加热后高硅无取向电工钢氧化层的微观形貌、结构组成及合金元素的偏析现象.结果表明:经高温加热后的高硅无取向电工钢氧化层主要包括4部分,分别为纯氧化铁层、铁橄榄石和氧化铁混合层、富Si区与贫Si区混合层、致密氧化膜层;高温氧化过程中会产生Si成分偏析现象,1240℃时Si的偏析深度可达130μm,不同深度偏析处的Si质量分数相差可达0.9%,且随着温度的降低,偏析程度逐渐减弱,直至消失.

The oxidation behavior of high silicon non-oriented silicon steel at different temperatures was studied by comparative experiments.Field emission scanning electron microscopy with an EDS detector was used to observe the micromorphology,structural composition,and segregation of alloy elements of the oxide layer of high-silicon non-oriented electrical steel after heating at different temperatures(1030~1240℃).The results show that the oxide layer of highsilicon non-oriented electrical steel after high-temperature heating mainly consists of four parts,namely pure iron oxide layer,fayalite and iron oxide mixed layer,Si-rich and Si-poor mixed layer,and dense oxide film layer;During the high-temperature oxidation process,Si component segregation occurs.The segregation depth of Si can reach 130μm at 1240℃.The difference in Si mass fraction at different depths of segregation can be as high as 0.9%.As the temperature decreases,the degree of segregation gradually weakens and finally disappears.