Evaluation of Plasticity and Creep Parameters From Tensile Stress–Strain Data for a Range of Strain Rates

A novel methodology is presented for evaluation of plasticity and creep parameters via analysis of experimental data obtained during tensile testing with several different strain rates. This offers a number of advantages over conventional creep testing. It involves the use of a simple numerical model, which can be implemented using a spreadsheet. The procedure has been applied to a standard stainless steel (SS301) at 700°C. At this temperature, the tensile response of this alloy (within the ‘quasi‐static’ range of strain rate) is ‘creep‐affected’. In addition, conventional creep testing has been carried out, with different fixed loads (corresponding to nominal stresses around and above the yield stress). Using the Miller–Norton equation to capture creep strain histories, the outcomes of these tests have been converted so that they correspond to those expected with a fixed true stress. Very close agreement is observed between the creep parameter values obtained with the two approaches.