TURBOMACHINES BLADES SHROUDS FROM HEAT-RESISTANT NICKEL ALLOYS RECONSTRUCTION METHOD Russian patent published in 2018 - IPC B23P6/00 B23K9/04 C23C26/00 

FIELD: technological processes.

SUBSTANCE: invention relates to the field of welding and surfacing, and can be used during made of heat-resistant nickel alloys worn or damaged turbine blade shrouds repair. Turbomachines blades shrouds from heat-resistant nickel alloys rebuilding method involves coating with the damaged layer removal from the shroud, shroud surfacing with the high-temperature nickel alloy to the specified dimensions, and the surfaced section machining, then conducting the blade annealing and the wear-resistant coating application to the surfaced shroud portion. Shroud surfacing is performed with the high-temperature nickel alloy with the higher linear expansion temperature coefficient than in the blades shrouds heat-resistant nickel alloy. As the wear-resistant coating, the carbide based wear-resistant material is used with a cobalt binder with the lower temperature expansion coefficient than in the blade shrouds heat-resistant nickel alloy. In particular embodiments of the invention, the shroud surfacing is performed with the heat-resistant nickel alloy ZhS32 with the linear expansion temperature coefficient of 17.6⋅10^-6 K^-1 in the temperature range from 800 to 900 °C with the heat resistance characteristics not lower than in the turbomachine blades shrouds heat-resistant nickel alloy, which is the heat-resistant nickel alloy ZhS26 with the linear expansion temperature coefficient of 15.2⋅10^-6 K^-1 in the said temperature range. As the carbide based wear-resistant material with cobalt binder, using the CM-64, XTH-61, XTH-62 with the linear expansion coefficient of α_t=(7.2–7.8)⋅10^-6 K^-1. Removal of coating with damaged layer from the blade shroud is performed by the diamond grinding. Blade annealing is performed under the neutral gas or under vacuum of 10^-3–10^-4 mmHg at the temperature not exceeding 1,050 °C.

EFFECT: enabling increase in the turbine blades reliability, service life, the blade shroud performance at the high heating temperature of 1,000–1,060 °C and the surfaced areas quality, at that, enabling the shrouds geometric dimensions and shape restoration high accuracy, and enabling the quality of repair.

5 cl