Tempering of steel

Tempering of martensitic steels involves the segregation of carbon, the precipitation of carbides, the decomposition of retained austenite, and the recovery and recrystallization of the martensitic structure. Because these several reactions overlap and occur on such a fine scale, it is only recently that our knowledge of the resulting structures has become reasonably complete. Our present understanding of the processes involved in the tempering of iron-carbon martensites and how they are affected by alloying elements is reviewed.