Stainless steel is an iron and chrome alloy so persistent thanks to its chrome oxide on its surface. However, sometimes corrosion appears and its consequences are very serious. Now they seem to have found the cause, so it seems that the way has been opened to increase corrosion resistance.
Researchers at the University School of London have studied the corrosion of stainless steel. Apparently, these small points of corrosion that eventually become holes appear everywhere. However, using a special microscope, they have seen that these points are in moments of absence of chromium.
Apparently, sulfur impurities below a million millimeter take longer to solidify than steel and when the ingot cools, they take over the surrounding chromium. Consequently, the surrounding steel is unprotected from chrome oxide.