一种管板用18MND5型低碳合金钢的N/Al比控制方法的尝试

An Attempt to Control the N/Al Ratio of 18MND5 Type Low Carbon Alloy Steel for Tube Plate

通过电炉炉后一次性加入足够的沉淀脱氧剂Al块、VD前保证钢液氧含量不大于25×10^(-6)、VD后采用底吹氮气方式调整钢中氮元素含量、铝线微调Al含量的方式控制钢中N/Al值范围达到0.54~0.81,提高铝回收率,降低18MND5型低碳合金钢韧脆转变温度,显著提高钢的低温韧性。

After tapping from the electric furnace,enough precipitation deoxidizer Al blocks have been added at one time,and the oxygen content in the molten steel has been ensured not more than 25×10^(-6) before VD,and the nitrogen content in the molten steel has been adjusted by bottom blowing nitrogen after VD,and Al content has been finely adjusted by the aluminum wire.The method controls the N/Al value range of steel to reach 0.54~0.81,improves the aluminum recovery rate,reduces the ductile-brittle transition temperature of 18MND5 type low-carbon alloy steel,and significantly improves the low-temperature toughness of the steel.