IF钢板坯表层大尺寸夹杂物的三维分布

IF钢铸坯表层大尺寸夹杂物分布对冷轧钢板表面质量有较大影响。采用ASPEX自动检测法与逐层刨削法研究了IF钢铸坯表层20 mm内中100 μm以上夹杂物的三维分布。铸坯表层20 mm内夹杂物共分成3类,气泡、氧化铝+气泡、块状氧化铝,数量比例分别为72%、26%和2%。结合水模型研究了结晶器内大尺寸夹杂物被凝固坯壳捕获行为,结果表明,在现有浇铸工况下结晶器内大尺寸夹杂物主要集中在上回流涡心处与浸入式水口下部等结晶器“死区”位置。消除结晶器内死区有助于减少铸坯表层大尺寸夹杂物,提高轧板表面质量。

Three-dimensional distribution on macro inclusions in surface layer of IF steel slabs

The distributions of macro-inclusions plays an significant role in surface quality of cold rolled steel sheets. The three-dimensional distribution of inclusions over 100 μm in 20 mm surface of IF steel slab was studied by ASPEX automatic detection method and layer-by-layer planing method.It is found that three kinds of macro inclusions were detected, bubbles, alumina plus bubbles and brick alumina and their number percentage occupy 72%、26% and 2%,respectively. The large sized macro inclusions mainly concentrated within the upper roll center zone and stagnant zone below the submerged entry nozzle (SEN) bottom according to the full scale water modeling of mold domain. Eliminating the dead zone in mold is helpful to reduce the large size inclusions and improve the surface quality of rolled products.