Corroding method of DD5 single-crystal high-temperature alloy turbine blade

Abstract

The invention discloses a corroding method of a DD5 single-crystal high-temperature alloy turbine blade. The method includes the following steps of firstly, sand blasting; secondly, primary chemical corroding, wherein a 40% ferric trichloride solution and a 37% hydrochloric acid solution are used for preparing a corroding solution, and chemical erosion is conducted on a cast in the first step for9 minutes; thirdly, primary washing, reactants adhering to the surface of the cast and generated during chemical erosion in the second step are washed away through an ultrasonic washing machine, the ultrasonic frequency is 20 KHz, the water temperature is 50 DEG C, and the washing time is 5 minutes; fourthly, secondary electrochemical corroding; fifthly, secondary washing; sixthly, tertiary electrochemical corroding; seventhly, neutralizing, wherein the cast in the six step is placed in a 5% NaHCO3 room-temperature solution to be soaked for 3 minutes, and acid liquid on the surface of the castis neutralized; eighthly, drying. The corrosion effect is clear, and it can be avoided that due to local excessive corrosion, surface structure and appearance size of the cast are not qualified.

Description

technical field [0001] The invention relates to the technical field of turbine blade production, in particular to a DD5 single crystal superalloy turbine blade corrosion method. Background technique [0002] DD5 single crystal superalloy is the second-generation cast single crystal master alloy developed in my country. Single crystal turbine blade means that the entire turbine blade consists of one grain. After the single crystal turbine blade is cast, it is necessary to use the corrosion method to show the grain growth during the smelting and solidification process. The traditional method uses the hydrochloric acid hydrogen peroxide (9:1) method to corrode. The hydrochloric acid is extremely volatile, and the hydrogen peroxide and the hydrochloric acid solution also produce chemical reactions, resulting in a ratio of The composition of the solution is unstable, and it is easy to cause unclear corrosion effect or local excessive corrosion, resulting in unqualified surface st...

AI Technical Summary

Problems solved by technology

After the single crystal turbine blade is casted, it is necessary to use corrosion method to show the grain growth during melting and solidification. The traditional method uses hydrochloric acid hydrogen peroxide (9:1) method for corrosion. Hydrochloric acid is very volatile, and hydrogen peroxide and hydrochloric acid solution also produce chemical reactions, resulting in The composition of the solution is unstable, which can easily lead to unclear corrosion effect or local excessive corrosion, resulting in unqualified casting surface structure and appearance size, thereby reducing the product qualification rate