稀土Y对6.5%Si高硅钢热轧和温轧组织织构演变的影响

摘要：以无稀土与含质量分数为0.03%的Y的6.5%（质量分数）Si高硅钢为研究对象，经过热轧、常化、温轧及退火工艺制备出0.5mm高硅钢薄板，采用EBSD、SEM和EDS测试技术，研究了稀土Y对高硅钢热、温轧组织织构演变的影响。结果表明，热轧板中以{001}〈110〉和{110}〈001〉织构为主，常化板织构类型遗传了热轧板，添加稀土Y削弱了热轧、常化板中整体织构强度。含Y高硅钢较无稀土高硅钢温轧剪切带增多，位错密度增加，α织构减弱且γ织构增强。随着退火温度升高，温轧板以{001}〈140〉为主的λ织构和{114}〈481〉为主的α*织构强度不断增强。添加稀土Y削弱了相同退火温度下温轧板的λ织构与α*织构的强度，然而η织构却有所增强，这与稀土Y促进剪切带形核有关。添加质量分数为0.03%的Y具有细化晶粒的作用，细小弥散的稀土Y氧化物阻碍晶界迁移是导致高硅钢温轧板再结晶晶粒细化的重要原因。

Effects of rare earth Y on microstructure and texture evolution of 6.5 wt.% Si high silicon steel during hot and warm rolling

0.5mm thick 6.5 wt.% Si high silicon steel sheets containing 0.03 wt.% Y and without Y were prepared by hot rolling, normalizing, warm rolling and annealing, and the effects of rare earth Y on the microstructure and texture evolution of high silicon steel during hot and warm rolling were investigated by EBSD, SEM and EDS. The results show that {001}〈110〉 and {110}〈001〉 textures were the main textures in hot rolled sheets, and normalized sheets inherited the texture types of the hot rolled sheets. Y addition weakened the overall texture intensities of hot rolled and normalized sheets. Compared with high silicon steel without Y, high silicon steel containing 0.03 wt.% Y had more shear bands, higher dislocation density, weaker α texture and stronger γ texture. With the increase of annealing temperature, the strength of λ texture dominated by {001}〈140〉 and α * texture dominated by {114}〈481〉 of warm rolled high silicon steel sheets increased continuously. The addition of rare earth Y weakened the λ and α* texture intensities of warm rolled sheets at the same annealing temperatures, but the η texture was enhanced, which was related to the promotion of shear band nucleation by Y addition. The fine and dispersed Y oxides hindered grain boundary migration, that was an important reason for grain refinement of recrystallized high silicon steel warm rolled sheets with 0.03 wt.% Y.