Surface grain corrosion method for IN718C nickel-based superalloy aviation bearing seat

Abstract

The invention discloses a surface grain corrosion method of an IN718C nickel-based superalloy aviation bearing seat. The surface grain corrosion method comprises the following steps: polishing the surface of a casting to remove a corrosion layer; removing casting surface pollutants through sand blasting, so that the casting surface is in an activated state; chemically etching the casting soaked in the hot water in a corrosive liquid prepared from copper sulfate pentahydrate, a hydrochloric acid solution and water; swinging and cleaning with cold water until no corrosive liquid is left on the surface; washing with a high-pressure water gun after neutralizing the casting; and performing surface detection after hot water soaking and drying. Compared with an existing hydrochloric acid and ferric trichloride proportional corrosion and hydrofluoric acid and nitric acid bleaching method, the corrosion method using the proportion of copper sulfate, hydrochloric acid and water has the advantages that the operation steps are simplified and safe, the corrosion process parameters are more controllable, the process is stable, surface crystal grains are clearly and uniformly displayed, the production repeatability is good, the cost is low, and the qualified rate of corrosion production is improved.

Description

technical field

[0001] The invention relates to the technical field of nickel-based alloy surface treatment, in particular to a surface grain corrosion method of an IN718C nickel-based high-temperature alloy aviation bearing seat. Background technique

[0002] IN718C is a precipitation-strengthened nickel-based superalloy with body-centered tetragonal "γ" phase as the main strengthening phase. It has high strength, plasticity, excellent corrosion resistance and good welding performance between -253 ° C and 700 ° C , is a key material commonly used in the aviation field. After the IN718C nickel-based high-temperature alloy aviation bearing seat is solution treated, it is necessary to use the corrosion method to show the grain growth during the solution treatment. The traditional corrosion method first corrodes with hydrochloric acid and ferric chloride (FeCl3 6H2O), and then uses hydrofluoric acid and nitric acid in a 1:1 ratio to bleach until the grains appear. Both hydrofl...

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