Alloying and heat treatment of steels with bainitic structure
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To ensure a good complex of mechanical properties, the alloying of bainitic steels has to be carried out in such a way that isothermal hardening is accopanied by the formation of carbidefree (lower) bainite with stable residual austen
Alloying steels with silicon and aluminum, and also reducing the carbon content extends the time up to the onset of carbide formation in the bainite reaction and provides the possibility of obtaining carbidefree bainite with carbon enriched stable residual austenite.
Hardened steels whose structure contains carbidefree bainite of different morphology and martensite have to be tempered at 300°C for 1–3 h. Such tempering entails additional disintegration of residual austenite with out carbide segregation and its enrichment with carbon; this enhances the impact toughness of the steel.
KeywordsSilicon Mechanical Property Carbide Heat Treatment Austenite
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