METHOD OF LASER TREATMENT OF SURFACE OF STEEL BLADES OF TURBINES OF POWER PLANTS Russian patent published in 2021 - IPC B23K26/342 B23P6/00 B23K26/70 

FIELD: turbines or turbomachines.

SUBSTANCE: invention relates to a method of processing surface of steel blades of turbines of power plants. Coating is multilayered. First, surface is desorbed after machining from organic and inorganic compounds and foreign particles by laser beam in protective gas medium. Thereafter, controlled laser remelting is performed up to 2 mm with simultaneous structuring of blade material by isothermal annealing with subsequent hardening of surface layer to HRC 40–45 at depth of 0.3–1 mm and high temperature tempering to obtain strong base of alloying process. Allocation of working surface of blade is performed using cobalt-nickel powders and with high-temperature tempering. During laser doping, radiation power P is varied in range of 300 to 2,500 W, and/or speed of movement of radiation source V in range of 0.1 to 0.01 m/s, and/or amount of powder material G supplied from 3 to 15 g/min. Direct laser synthesis of the working surface of the blade, including edges, is performed by controlled solid-phase sintering using polymetallic composite powder materials, reinforced with ceramic fibers with mustache to depth of up to 30 % of main layer.

EFFECT: technical result consists in obtaining a high-quality powder coating, having high crack resistance and strength in cyclic loads, high wear resistance and adhesion of the deposited layer to the base material.

3 cl