Production of Ultralow-Carbon Steel by Improving Process Control at RH Degasser

摘要

With the increasing market need for continuously annealed cold rolled sheets, customer demands lower level of carbon in ultra low carbon steel to obtain good formability. The decarburization is carried out at RH degasser to produce ultra low carbon steel. Higher RH out carbon leads to the down-gradation of that heat. A study was carried out to understand the impact of various process and quality parameters that affect RH out carbon. In this paper, the knowledge acquired during the processing of ultra low carbon heats at LD2 steel making shop of TATA Steel Jamshedpur Works has been discussed. The impact of vacuum pump down time, time under deep decarburization, material addition practice for different grades, snorkel condition and off-gas analysis were studied. The study led to several improvements in the existing system which significantly improved the control level in terms of RH out carbon.