优化钙处理工艺减少管线钢B类夹杂物

Reduction of B type inclusions in pipeline steel by optimizing calcium treatment

为了减少管线钢中B类夹杂物的生成,开展了钙处理工艺优化研究。研究发现,钢中钙含量较高时,易生成由低熔点钙铝酸盐组成的B类夹杂物。据此提出低钙含量的钙处理优化工艺并开展工业试验。钙处理工艺优化后,夹杂物主要为高Al2O3含量的CaO-Al2O3,由于存在高熔点相,大部分夹杂物在轧制过程中基本未发生变形,而大尺寸夹杂物则主要发生脆性破碎,这与工艺优化前低熔点夹杂物的塑性变形明显不同。轧板中基本未观察到长宽比大于5的夹杂物,且大尺寸夹杂物的数量显著减少。通过钙处理工艺优化,管线钢中B类夹杂物得到了很好的控制。

In order to reduce the formation of B type inclusions in pipeline steels,the optimization of calcium treatment process was carried out.It was found that when the calcium content in steel was high,B inclusions formed by calcium aluminates with low melting point were easy to generate.Accordingly,the optimization of calcium treatment process with low calcium content was put forward and the industrial test was carried out.After the optimization of the calcium treatment process,the inclusions were mainly CaO-Al2O3 with high Al2O3 content.Due to the existence of high melting point phase,most inclusions were basically not deformed during the rolling process,while the large inclusions were brittle fracture,which was obviously different from the plastic deformation of the low melting point inclusions before the optimization.The inclusions with length width ratio greater than 5 were almost not observed in the rolled plate,and the number of inclusions in large size decreased significantly.By optimizing the calcium treatment,B type inclusions in pipeline steel have been well controlled.