An internal state variable (ISV) framework is used to predict the rate and degree of strain relaxation associated with the stage I, low temperature tempering of martensite. A single variable tracks the change in volume between the tempered an untempered structures. The rate at which this occurs is taken to be a function of martensite fraction, temperature, degree of tempering, and carbon concentration. Experimental dilatometty data is used to both fit and validate the model.
展开▼