THE EFFECT OF SOME HEAT TREATMENT PARAMETERS ON THE PROPERTIES OF AISI D2

AISI D2 is usually vacuum hardened then tempered several times. Deep cold treatment between the hardening and tempering processes could improve the final properties. Hardened blocks of AISI D2 were then subjected to various combinations of single and multiple tempering steps and deep cold treatments. The results showed that for all austenitising temperatures a single deep cold treatment followed by a single tempering cycle was sufficient to reduce the retained austenite to below 1%. The colder the cold treatment temperature and the longer the treatment time, the higher the hardness values that could be achieved. The deep cold treatment did not affect the fracture toughness or distortion.