272-paper-转炉到连铸钢水增氮的试验研究-英文.docVIP

nitrogen increasing OF working procedure between steelmaking and casting CHEN Zhiping DONG Hanjun (Shanghai Meishan IronSteel Corp. of Baosteel Group) Abstact Generally,nitrogen in the steel is a harmful element to the machining quality.During steelmaking ,there are many chances for nitrogen increasing .This article investigates the law of nitrogen changing from BOF to CC,finds that tapping、blowing argon、LF、CC are the mainly working procedures of nitrogen increasing.CC is the most seriously site. Reason analyses and improvement methods are given according to the existen conditions. Keywords nitrogen increasing BOF continuous casting 1. Introduction (chief character MeiShan Steel making device) As normal, nitrogen in steel is a harmful element. For a instance, the segregation of Fe4N will cause effectiveness of period of time and blue brittle for low carbon content steel; as nitrogen get pass a definite content, it will form babble and lossen; nitrogen can form pointed inclusion group with Ti, Al etc in the steel; besides, nitrogen in steel can degrade the toughness, blasticity; weldability; electrical conductivity; magnetic conductivity and increase the lost of magnetic delaying. So we should decrease the content of nitrogen in steel except hot enduring steel and stainless steel, high quality steel demands the nitrogen content under 0.008%[1]. because the nitrogen is the chief part of the air, so it is easy to get in during the steel making-cc procedure, and it is difficult to eliminate by normal chemical reaction at normal condition, so drainage of nitrogen is still the problem of steel making. The VD technique(e.g. RH) could drain a part of nitrogen, but normally under the condition of high. So now if we want to decrease the nitrogen content at first we need to degrade the nitrogen in material as far as we can, then avoid the increasing during each procedure, tapping and cc are chief working procedure as normal. The series of pipeline steel are the objects