A review of experimental studies of creep and creep rupture strength (2004–2021)

The paper reviews studies conducted between 2004 and 2021 for various metal materials (magnesium-lithium alloy, copper, aluminum alloy, titanium alloy, steel, nickel alloy) in the temperature range from 20 to 1100 °C. In those studies the test results were obtained for isothermal creep under uniaxial tension and complex stress. The number of such studies is limited. This review does not include studies dealing with the chemical interaction of the environment with a metal material. Among these studies there are little-known and unique results. In one of those studies, the creep of a magnesium-lithium alloy at normal temperature was considered for the first time. In another study, creep curves for heat-resistant steel were supplemented with experimental stress–strain diagrams in a wide range of high temperatures. Another distinctive study, for the characteristic times of the creep process, compares photographs of changes in the microstructure and the creep curve up to the rupture time. The review lists studies that found an ambiguity in the effect of biaxial tension on the rupture time in comparison with uniaxial tension. It enumerates complex equivalent stresses with the possibility of describing the relative difference in the rupture time under uniaxial tension, biaxial tension, and triaxial tension.