X60管线钢硫化夹杂物钙处理技术研究

Analysis on Calcium-treatment of Sulphide Inclusion in Pipeline Steel

在对管线钢中硫化物的作用综合分析的基础上,依据冶金热力学原理,结合莱钢生产实践,分析计算了X60管线钢硫化物的钙处理工艺条件,并对莱钢生产的管线钢中的夹杂物进行了检测分析.结果表明,莱钢生产管线钢时,大部分炉次精炼终点氧含量高于理论计算得到的钙处理所需的目标氧含量3.42×10-6,钢中钙含量未达到理论计算得到的钙硫平衡时所需的钢中溶解钙含量,硫化物夹杂物变性并不完全,钢中存在MnS,MnS-CaS复合夹杂物.

On the basis of analysis of the effect of the sulfide on pipeline steel, with metallurgical thermodynamics principle and production practice of LaiwuSteel, the production conditions in calcium-treatment of sulphide inclusion in X60 pipeline steel were analyzed. The inclusions in the steel were examined. The results showed that during the smelting of pipeline steel in LaiwuSteel, the final dissolved oxygen content in molten steel for most of the heats was higher than the theoretical value of 3.42×10-6 required for calcium-treatment, and the calcium content in molten steel did not reach the equilibrium value of calcium and sulfur, therefore, the sulfide inclusions had not been modified completely, there were some MnS and MnS-CaS in the pipeline steel.