Constitutive Relations of the Mechanics of a Damaged Medium for Evaluating the Creep-Rupture Strength of Structural Alloys

The main regularities of the degradation of structural materials (metals and alloys) resulting in a decrease in creep-rupture strength were investigated. A mathematical model describing the viscoplastic deformation and damage accumulation in polycrystalline structural alloys in creep was developed using the equations of the mechanics of damaged media. The paper presents the results of experimental studies of the short-term creep of 12Kh18N9 steel and VZh-159 high-temperature alloy at constant temperature and different stresses set in the samples and the results of experimental studies of creep recovery in some structural steels. Deformation and damage accumulation were studied numerically and the results were compared with the data of full-scale experiments.