AGING BETWEEN 300 AND 450-DEGREES-C OF WROUGHT MARTENSITIC 13-17 WT-PERCENT-CR STAINLESS-STEELS

Martensitic stainless steels containing 13-17 wt-%Cr, some also containing nickel and some having precipitation hardening additions, have been aged between 300 and 450-degrees-C for times up to 30 000 h. For all the steels examined, the aging response takes the form of an increase of strength and hardness, correlated with embrittlement. The rate and intensity of aging increase with increasing chromium and molybdenum concentrations. In addition, two steels exhibit some temper embrittlement on long term aging at 400-degrees-C; such embrittlement of these materials is not expected in service at temperatures up to 300-degrees-C. A general method of prediction of the mechanical properties of these steels as a function of aging conditions is proposed.