Martensite

Heat Treatment

Определение

A hard, brittle microstructure formed in steel when austenite is cooled rapidly enough to suppress diffusion, trapping carbon in a supersaturated body-centered tetragonal lattice. It is the hardest microstructural constituent in steel.

Подробное объяснение

Martensite formation is a diffusionless (displacive) transformation that begins at the martensite start temperature (Ms) and completes at the martensite finish temperature (Mf). The hardness of martensite increases strongly with carbon content, reaching approximately 65 HRC at 0.8 wt% carbon. Fresh martensite is too brittle for most engineering applications and must be tempered to restore adequate toughness.