METHOD FOR ESTIMATION OF THE AVERAGE LOCAL WORKING TEMPERATURES AND THE RESIDUAL RESOURCE OF METAL COATINGS OF GAS-TURBINE BLADES
P. G. Krukovskii and K. A. Tadlya UDC 539. 219:620.193.2 A new method is proposed for estimation of the average local operating temperatures and the residual service life (resource) of protective MCrAlY metal coatings of gas-turbine blades after a certain time of operation on the basis of experimental data on the residual content of aluminum in the coating of a blade and/or the width of its first depletion zone. A physical and a mathematical model of the processes of oxidation and diffusion of aluminum in the coating-blade alloy system, accounting for the kinetics of formation of the diffusion zone, are presented. Results of calculation of the local working temperatures and the residual resource of the coating of a blade at local points along the outline of the blade cross section by the method proposed with the use of data on the width of the first depletion zone are given. Institute of Technical Thermal Physics, National Academy of Sciences of Ukraine, 2a Zhelyabov Str., Kiev, 03057, Ukraine; email: kruk@i.kiev.ua. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 80, No. 3, pp. 16-23, May-June, 2007. Original article submitted November 1, 2005.