Ferritic steel has a body-centred cubic structure and austenitic steel, non-ferrous metals like aluminium, copper and nickel have the face-centred cubic structure.
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Manganese preserves an austenitic structure in the steel as does nickel, but at a lower cost.
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Austenitic, or 300 series, stainless steels make up over 70% of total stainless steel production.
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When steels with less than 0.8% carbon, known as a hypoeutectoid steel, are cooled from an austenitic phase the mixture attempts to revert to the ferrite phase, resulting in an excess of carbon.