Deformation and long term strength of structural elements at high temperature fretting wear and corrosion conditions

The influence of the environment (water, hydrogen etc.) can essentially limit the long-term strength of structural elements due to material degradation. In the case of contacting the different surfaces the deterioration of structural properties continues. The problem of corrosion and wear of machine-building structures has recently been in the focus of attention of researchers and engineers, however, the development of a computational method for estimating the interaction of high-temperature phenomena, such as creep and hidden damage accumulation, continues to be an urgent task. The problem consists in the significant variation of the stress-strain state during long term operation. The existing methods for calculating the strength of structures under the influence of corrosion and wear, as a rule, do not take into account these changes and the accumulation of damage, which can lead to incorrect life estimates.

Structural elements operating at high temperatures under the influence of aggressive media, on the one hand, are among the most expensive, and on the other hand, their failure can lead to environmental damage. This applies to gas turbines and gas turbine engines, automobiles, chemical production equipment etc. Failure and fracture of their structural elements lead to financial losses, is dangerous and unacceptable from the point of view of human safety.

Experimental methods for evaluating high-temperature deformation and fracture under the influence of aggressive media and contact interaction of various details are expensive and often quite hazardous to the health of personnel. That is why the development of a new approach and a numerical method for analyzing creep and damage accumulation in structures affected by corrosion and fretting wear is an important task both at the design stage as well as for the assessing the safe operation time of already operating equipment.