| 摘要 |
PURPOSE:To enable to repair the stationary blade of a gas turbine by a simple and firm method of high quality, by using heat resistant brazing material of cobalt group consisting of the same constituent as of the base material of a stationary blade, and by repairing the defective part by the method of brazing in a protective atmospheric furnace. CONSTITUTION:The stationary blade of a gas turbine, which is provided with an outer wheel 1, an inner wheel 2 and nozzle blades 3, is made of heat resistant alloy of cobalt group as a precision molding. In this case, in order to repair a crack 4 occurred at the end of a nozzle balde 3, first, the crack part is treated to be melted in a highly vacuum atmosphere using a vacuum heat treating furnace, for example. Then, Cr carbide and other harmful deposited substance which have deposited on the blade during high-temperatured operation for a long period are subjected to solid solution. In such a manner, the oxide adhered on the inside of a crack 4 is scattered away from the blade, as well as to recover the toughness in the material of the blade. Next a heat resistant brazing material 5 of cobalt group is coated on the crack 4, and the nozzle blade 3 is inserted into the vacuum heat treating furnace again to melt the brazing material 5 to be penetrated into the crack 4 to repair it. |
