Effect of Cu on the Anti-Bacterial Properties of Type 304 Stainless Steel

摘要

Recently, in the line with the growing interest of sanitary problem, the requirement for the development of anti-bacterial material has been an issue with more weight. In Japan, not only some steel makers already completed the development of the anti-bacterial stainless steel, but other makers are also showing an interest in that subject. The function of anti-bacterial power of stainless steel is closely related with the addition of Cu element. In this case, Cu decomposes as Cu~2 and reacts with COA-SH enzyme which acts as a catalyst in respiratory process of bacteria, resulting in deactivation of the enzyme. The current study derived an optimum anti-bacterial alloy composition, proper process conditions including heat treatment and the overall comparison with the previous developed POSCO-304J1 stainless steel. With the proper heat treatment the anti-bacterial power of the developed alloy is increased due to the uniform distribution of #epsilon#-Cu precipitates (0.5 approx 1.0#gamma#m) restraining the formation of passive film on the steel surface.