Abstract:  The law of increasing nitrogen by RH withdrawing pump and the effect of nitrogen content on inclusions in ultra-low carbon enamel steel are studied. The results show that the time of increasing nitrogen by RH withdrawing pump ≤ 25 min, the relationship between the time of withdrawing pump and the nitrogen content in steel is basically in accordance with a quadratic formula γ = -0. 226 x² + 9.429 x +31.21. The inclusions in enamel steel are mainly the second phase precipitates containing Ti and a small amount of Al₂0₃ particles. The main composition of small inclusions is TixS, and that of large inclusions is TiN. The nitrogen content of conventional enamel steel is 0.003 8% , and the nitrogen content of two nitrogen increased enamel steel is 0.010 8% and 0. 012 7%. The total inclusions in the corresponding steel are 355. 61, 545. 74 and 558. 77μm²/mm² respectively. The number of inclusions in each size range in conventional enamel steel is the least. Considering hydrogen storage property and RH nitrogen increasing time of enamel steel, the nitrogen content in steel is suitably controlled around 0. 01% .

摘要： 研究了超低碳搪瓷钢RH减泵增氮的规律以及搪瓷钢中氮含量对夹杂物的影响。结果表明,RH减泵增氮25 min以内,减泵时间与钢中氮含量的关系符合二次项公式γ=-0.226x²+9.429x+31.21。搪瓷钢中夹杂物主要是含Ti的第二相析出物及少量单独的Al₂O₃颗粒。小尺寸夹杂物成分以TixS为主,大尺寸夹杂物成分以TiN为主。常规工艺搪瓷钢中氮含量为0.0038%,两个增氮的搪瓷钢中氮含量分别为0.010 8%、0.0127%,对应的钢中夹杂物总量分别是355.61、545.74、558.77 μm²/mm²。常规工艺搪瓷钢中各个尺寸区间的夹杂物数量都是最少的。考虑搪瓷钢储氢性能和RH增氮时间,钢中氮含量宜控制在0.01%左右。