【摘要】 通过实验测定、金相观察和理论分析,系统研究了稀土在洁净BNbRE重轨钢中的赋存状态和存量的变化规律,以及其对钢的硫化物夹杂、微观组织及性能的影响作用机制。研究发现,在钢洁净度大幅度提高的条件下,稀土在钢中的作用机制有所变化,微量的稀土起到实现净化钢液、变质夹杂物和微合金化作用,而且作用效果非常稳定。随着钢洁净度的提高,稀土加入量可以适当降低。在本实验条件下,洁净BNbRE重轨钢的稀土最佳加入量为～0.01%,此时洁净BNbRE重轨钢的塑性和冲击韧度得到显著改善。更多还原

【Abstract】 The mechanisms of RE in clean BNbRE steel were studied by means of experimental measurement, microscopic structure observation and theoretical analysis. For BNbRE steel, the content of RE were measured, and the effects and the mechanisms of RE on sulfide inclusions, microscopic structure and properties of steel were investigated. With increasing the cleanness of steel, the mechanisms of RE in steel are changed to certain degree. A little of RE has the effects of cleaning, modifying inclusions and alloying in clean steel. With increasing the cleanness of BNbRE steel, the addition of RE should be decreased properly. Under the experimental condition, the optimum addition of RE is ～0.01% for clean BNbRE steel, while RE can evidently improve the plasticity and the impacting toughness of BNbRE steel.更多还原