METHOD OF REFINING HIGH CR FERRITIC STAINLESS STEEL FOR LOWERING C

摘要

A refining method of high chrome ferritic stainless steel for reducing carbon is provided to improve elongation ratio of the stainless steel and the grain corrosion resistance by measuring accurate agitating intensity and performing VOD(Vacuum Oxygen Decarburization) using the same. A refining method of high chrome ferritic stainless steel for reducing carbon comprises a step of attaching a vibration sensor to the exterior wall of a VOD tank, a step of measuring only the specific frequency among the frequencies outputted from the vibration sensor, and a step of controlling the bottom bubbling intensity of an oxygen blowing decarbonzier and a vacuum decarbonzier during secondary refining. The attachment position of the vibration sensor is less than 30cm from the tank exterior wall which is located on the straight line with a mount contacting a handle of a ladle in the VOD tank. The specific frequency is in a frequency band of 10~45Hz. The bottom bubbling intensity that the vibration index measured from the vibration sensor is compensated with the bottom bubbling flow rate is controlled to 400~600 so that the carbon concentration less than 60ppm is obtained finally.