Here are some links. BUt frankly, everything about steel is microstructure, which by definition is NANOscale... Martensitic structure is nanoscale. establishing fine austenitic grain size by innoculating with trace amounts of aluminum, vanadium, or niobium results in nano level size particles distributed which inhibit austenitic grain growth, thus results in change of properties.
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People say between two opposed opinions the truth lies in the middle. Not at all! Between them lies the problem, what is unseeable,eternally active life, contemplated in repose. Goethe