IMPROVEMENT OF CORROSION RESISTANCE OF STAINLESS STEEL

摘要

PURPOSE:To stably improve the corrosion resistance of a stainless steel material having a lustrous surface without deteriorating the luster by immersing the steel material in a nonoxidative acid bath and holding it in the bath for a specified time. CONSTITUTION:A coil 1 of a stainless steel material having fine surface luster such as a 2B stainless steel material or a bright-annealed stainless steel material is continuously uncoiled, immersed in a nonoxidative acid bath 2 and held in the bath 2 for such a time that the natural potential suddenly changes to the lower side and the surface luster rate does not suddenly drop. A reference electrode 4 is placed in a treatment tank 3 contg. the acid bath 2, the potential difference between the electrode 4 and one end of the coil 1 is continuously measured and a sink roll 5 is moved up and down according to the measured difference to control the immersion time.