ANALYSIS OF FIRST ORDER KINETICS FOR TERTIARY CREEP IN AISI 304 STAINLESS STEEL

摘要

The results of constant load creep tests on AISI 304 stainless steel at 873 and 973K for different test conditions were found to obey the first order kinetics for tertiary creep. Distinct master creep curves were obtained at 873 and 973 K with a separate set of constant values of K', ε_t,β' and C_MG. A relationship between steady-state creep rate _ε_s time spent in tertiary creep t_t and limiting tertiary creep strain ε_t is formulated as ε_s. t_t/ε_t = constant and is found to be valid for all test conditions. Further, this relation is identical to the modified Monkman Grant relation (MMGR) for the conditions satisfying f=1/λ;it is postulated that the validity of MMGR is a consequence of first order kinetics.