Hi everyone, I'm a chemist in search of a basic understanding of precipated hardness and how this imparts extreme corrosion resistance. I have become interested in a steel with the simple notation H-1. Is it simply the fact that carbon is at extremely low levels (0.15%) which allows the chromium to constantly form an oxide film on the surface? Thanks!!!!

Not exactly. Considering your interest is corrosion resistance, low carbon is enough to allow a good corrosion resistance. Carbon tends to concentrate on dislocations and joints. Precipitating in chromium carbides, it increases hardness but consumes chromium. Thus, oxyde layer THICKNESS is lowered. Chromimum oxyde layers appears on the whole surface, and its composition depends on quantity of chromimum and oxygen available, and thermal history, and so on.