不同浇铸阶段IF钢连铸板坯洁净度

Cleanliness of interstitial-free steel slabs produced in different casting stages

对采用转炉-RH精炼-连铸工艺生产的IF钢连铸板坯在不同浇铸阶段(开浇、正常、两炉交接及浇铸末期)的铸坯洁净度进行了较为细致地研究和对比分析.由于浇铸初期存在二次氧化及较大程度地增碳,开浇坯[C],[O]T,[N]含量远高于其他时间段的铸坯,并存在较大尺寸的簇群状Al2O3夹杂.正常坯夹杂主要为尺寸较小(≤30μm)的块状及少量簇群状Al2O3夹杂(≤40μm),交接坯及尾坯仍以较小尺寸的块状Al2O3夹杂为主,但存在极少量大于100μm的复合夹杂.

The cleanliness of IF steel slabs produced by the BOF-RH-CC process in different casting stages was investigated. Due to reoxidation at the casting beginning period, the [C], [O]τ, [N] contents of the first slab are higher than those of the slabs in other stages, and a few big size Al2O3 clusters exist in the first slab. The non-metallic inclusions in the normal slabs at the casting middle period is mainly small size A1203 blocks （≤30μm） and a few small size Al2O3 clusters （≤40μm）. The transition and end slabs have still mainly small size Al2O3 blocks, but appear few big size （≥ 100 μm） composite inclusions.