SWRH82B钢中夹杂物的研究与分析

Research and analysis of inclusions in SWRH82B steel

通过试验对SWRH82B盘条拉拔脆断问题进行研究,发现夹杂物是造成脆断的主要原因。用扫描电镜观测到夹杂物大小为10～30μm,用能谱分析仪测定出夹杂物各成分含量,指出夹杂物主要是Al2O3,CaO与SiO2等复合而成的脆性夹杂物,主要源于冶炼过程中的脱氧产物、转炉或电炉渣带来的夹杂物及耐火材料带来的夹杂物。通过控制合适的Ca与S,Ca与Al质量分数比值,以及对钢液中自由氧的含量和渣碱度的控制,可改善夹杂物的大小、形状和塑性,使夹杂物对SWRH82B的深加工性能影响降低到最小。

To research wire drawing brittle fracture of SWRH82B wire rod by test, it is discovered that inclusions are main cause for brittle fracture. The 10 - 30 micron inclusions are observed with SEM, the composition contents of inclusions are determined with Energy Disperse Spectroscopy. It is pointed out that the inclusions are main compound brittle inclusions of Al2O3 , CaO and SiO2 , which root in deoxygenated outcome of smelting, inclusions from slag of converter or electric furnace and inclusions from refractory. The size, figure and plasticity of inclusion can be improved by controlling suitable mass fraction ratio of calcium and sulfur, calcium and aluminium, the content of free oxygen in steel liquid and alkalinity of slag, which can make the effect of inclusions on deep workable property of SWRH82B wire rod reduce to minimum.