高温轴承钢中析出相的表征

摘要

The capability of the high temperature bearing steel is mostly influenced by the quantity,composition,size of precipitate phase in steel.After isothermal treatment,the high temperature bearing steel could form precipitates of inter-metallic phase and carbides.In order to study the precipitation behavior of precipitates in high temperature bearing steel under different heat treatment conditions,the suitable electrolytic conditions were selected by experiments,the precipitated phase was separated from the matrix by electrolytic extraction.X-ray diffraction (XRD) and scanning electron microscope(SEM) were used to examine their structure and modality.Separation and quantitative component analysis of precipitate phases were carried out by wet chemical analysis and inductively coupled plasma atomic emission spectrometry.The results showed that the electrolytic extraction temperature had a significant effect on the χ phase.The χ phase was insoluble in weak acid containing oxidant,but dissolved in 50%(V/V)H2SO4.With the increase of aging time,the M6C phase content increased significantly,the χ phase content reduced.The M6C phase was granular and the particle size was small,the χ phase was massive and the particle size was big.%高温轴承钢的性能,在很大程度上取决于钢中各种相的数量、组成和大小,轴承钢经过等温热处理,通常会形成碳化物相、金属间相等析出相.为了研究不同热处理条件下高温轴承钢中析出相的析出行为,实验选择了合适的电解条件,利用电解萃取方法将析出相从基体中分离.实验采用X射线衍射(XRD)和扫描电镜(SEM)研究了提取后析出相的结构及形貌,用化学湿法和电感耦合等离子体光谱仪对析出相的分离与定量成分检测进行研究.研究结果表明:电解萃取温度对χ相萃取量影响明显,χ相在含氧化剂的弱酸中不溶,在50%(V/V)H2SO4中溶解.随着时效时间的增加,M6C相明显增加,χ相减少.M6C相呈颗粒状,粒径细小,χ相呈块状,颗粒粗大.