莱钢SPHC钢铸坯中大型非金属夹杂物的分析

Analysis of Large Non-metallic Inclusions in SPHC Casting Blocks

利用大样电解法、LEO-1450型能谱分析仪和NEOPHOT-32型金相显微镜对SPHC钢铸坯中非金属夹杂物的种类、含量、来源、形状、尺寸进行分析研究。并针对尺寸特大（D≥150μm）的典型夹杂物进行详细分析，结果表明，铸坯中主要为O—Ca—Si—Al-Na—S复合型夹杂物。转炉出钢下渣量大、浮渣卷入、耐火材料侵蚀、以及钢液被空气二次氧化是钢中生成大型夹杂物的主要原因。并针对以上原因，提出相应工艺改进建议。

Analyses and investigations were done of the varieties,content,origins,shapes and sizes of non-metallic inclusions in SPHC casting blocks by the full-scale sample electrolytic method, Model-LEO-1450 EDAX analyzer and Model-NEOPHOT-32 metallographic microscope. Aimed at specially large typical inclusions （ D ≥ 1501axn）, a detailed analysis was carried out,showing that O-Ca-Si-Al-Na-S complex inclusions mostly exist in casting blocks ,based on which it was judged that big slag carry-over, dross involvement, refractory corrosion, improper operation in wire-feeding as well as the reoxidation of molten steel by air are the main causes of big inclusion formation in steel. The suggestions for improving corresponding technologies are put forth.