CSP工艺下稀土冷轧板退火过程中第二相析出的定量研究

Quantitative study on secondary phase precipitation of rare earth cold-rolled sheet during annealing in CSP process

研究了CSP工艺下稀土冷轧板冷轧后退火过程中的第二相析出行为,模拟了某企业685℃×9 h退火工艺,利用光学显微镜和X射线衍射仪分析了退火前后的微观组织和宏观织构的变化;采用非水电解分离法从试验钢中提取第二相粒子,并利用X射线衍射分析了第二相析出物类型;再使用化学法对退火过程中第二相析出量的变化进行了定量分析,并结合析出动力学计算分析第二相析出规律。结果表明,经过该退火工艺后,晶粒从典型的纤维状冷轧组织演变为再结晶饼形晶粒,非{111}织构有所减弱,{111}织构有所增强;试验钢中的第二相类型主要为MnS、Fe3C和Al N,MnS在退火过程中几乎不析出,Fe3C主要在室温到570℃升温过程中析出,Al N随着退火温度的升高而不断析出,在685℃附近析出最快。

Precipitation behavior of the secondary phases of rare earth cold-rolled sheet during annealing based on CSP process was studied.The 685 ℃ × 9 h annealing process of an enterprise was simulated. The change of microstructure and macroscopic texture before and after annealing ere analyzed by means of optical microscope and X-ray diffractometer. The secondary phase particles were extracted from the experimental steel by non-aqueous electrolysis separation method and the secondary phases were analyzed by X-ray diffractometer. The chemical method was used to quantitatively analyze the change of the secondary phases precipitation during the annealing process of the steel and the precipitation behavior of the secondary phases were analyzed by the precipitation kinetics calculation. The results indicate that after the annealing process,the grains of the steel are transformed from a typical fibrous cold-rolled microstructure to a recrystallized cake-shaped grain and non-{ 111} textures are weakened while { 111} textures enhanced. The secondary phases in the steel are mainly MnS,Fe3C and AlN types. In the scope of this experiment,MnS hardly precipitates during the annealing process. Fe3C mainly precipitates during the room temperature to 570 ℃.Al N precipitates continuously with the annealing temperature increasing,and precipitates fastest at about 685 ℃.