基于CSP工艺冷轧板第二相析出行为及其对组织的影响

Second phase precipitation behavior and its influence on microstructure of cold-rolled steel sheet based on CSP

采用TEM和光学显微镜对CSP工艺生产的冷轧基料和变形81.6%的冷硬板及模拟罩式退火工艺的退火板进行了组织分析。结果表明,在CSP工艺热轧、冷轧及退火各生产工序中都有纳米级第二相析出物的存在,Fe3C有聚集长大的趋势,MnS和AlN弥散分布在晶界和晶内,MnS尺寸为40～100 nm,在610℃时观察到50 nm左右AlN大量析出。第二相对退火过程中再结晶组织产生了重要影响,MnS及Fe3C对冷轧板组织的影响较AlN弱。随着退火过程的进行,晶粒长大,扁形晶粒增多。

Second phases and microstructure of cold-rolled base material based on compact strip production （CSP） , cold-rolled chilled sheet with 81.6% deformation, and simulated batch annealed sheet were analyzed with TEM and optical microscope. The results show that the nanoseale second phase precipitates exist in the steel sheets during every production stage from hot-rolling, cold-rolling to annealing, and the Fe3C has a coarsening tendency, the MnS and AlN precipitates distribute in both grain boundary and intragranular area. The size of the MnS is 40-100 nm, a lot of AlN particles are observed when the temperature reachs 610 ℃ and the size is about 50 nm. The second phase particles have a great effect on recrystallized microstructure during annealing, and the MnS and Fe3C particles effect less than that of AlN particles. The grains grow up during annealing, and the oblate grains also increase.