Cyclic Elastic Follow-up Behavior at Elevated Temperature : 3rd Report, Elastic Follow-up on 2.25 Cr-1 Mo Steel

Abstract

Cyclic elastic follow-up tests were carried out on 2.25 Cr-1 Mo steel at 600°C. The behavior of the relaxed stress and the elastic follow-up strain at the first elastic follow-up process were discussed with simplified inelastic analyses. When the Norton's creep law and a virtual triangle of elastic follow-up were used, it was found that the elastic-creep analytical method was a most useful technique to predict the elastic follow-up response on 2.25 Cr-1 Mo steel, as well as on SUS 304 steel. An inelastic strain range Δε_in produced in the cyclic elastic follow-up process was also examined and was compared with an analytical approximation. From analysis and experiments, it was verified that the shakedown condition of a structure can be achieved with simple limitations of an effective relaxed stress after a certain period and an effective yield stress of the material, as defined by the proposed model.