Pressurized electroslag remelting (PESR) has been widely used for preparation of high-quality high nitrogen steels. However, desulfurization might be limited by the pressurized-nitrogen atmosphere in the process. In this paper, the desulfurization behaviors of electroslag remelting in air and nitrogen pressure were investigated and further an appropriate method to improve the sulfur removal in PESR was explored. The results show that the ESR in air maintained relatively high and stable desulfurization ability, but the PESR provided worse sulfur removal owing to the lack of sulfur gasifying oxidation under N₂ pressure. With the decline of sulfur distribution coefficient (L_S) and the enrichment of sulfur in slag during the remelting, the desulfurization in PESR was gradually weakened. The level of gas pressure had little effect on sulfur removal. The Na₂O addition in conventional CaO-Al₂O₃-CaF₂ slags significantly increased the activity of desulfurizers and L_S, and slightly improved sulfur mass transfer in slags, then alleviated the negative effect brought by the reduction of desulfurization ability in PESR and achieved higher desulfurization degree. In addition, desulfurization in the remelting was mainly achieved at the liquid metal film of electrode tips, which was benefited from the great reaction specific surface area and high initial sulfur content.

加压电渣重熔（PESR）已被广泛用于制备高品质高氮钢。但是，脱硫可能会受到过程中加压氮气气氛的限制。本文研究了电渣在空气和氮气压力下的重熔脱硫行为，并探讨了改善PESR中硫去除率的合适方法。结果表明，空气中的ESR保持相对较高且稳定的脱硫能力，但PESR由于在N ₂压力下缺乏硫气化氧化而提供了较差的脱硫能力。随着硫分配系数的下降（L _S）和重熔过程中炉渣中硫的富集，PESR中的脱硫逐渐减弱。气压水平对硫的去除影响很小。在传统的CaO-Al ₂ O ₃ -CaF ₂炉渣中添加Na ₂ O显着提高了脱硫剂和L _S的活性，并略微改善了炉渣中的硫传质，从而减轻了PESR脱硫能力降低带来的负面影响。并实现了更高的脱硫度。另外，重熔中的脱硫主要在电极头的液态金属膜上实现，这得益于大的反应比表面积和高的初始硫含量。