Chemical pickling solution for removing surface oxide layer of high-temperature alloys containing elements Cr and Al and application of chemical pickling solution

Abstract

The invention relates to a chemical pickling solution for removing surface oxide layers of high-temperature alloys containing elements Cr and Al and application of the chemical pickling solution and belongs to the process field of removal of oxide layers of high-temperature alloys by using a chemical method. The pickling solution is prepared from the following components: 300-400g / L of hydrochloric acid, 400-450g / L of nitric acid and 100-150g / L of hydrogen peroxide and the balance of water. Aiming at the high-temperature alloy work-pieces of which the nickel base, iron base and cobalt base contain Cr and Al, the surface oxide layers are removed through the synergism of hydrochloric acid, nitric acid and hydrogen peroxide in specific concentration, the action mechanisms of above components are as follows: hydrochloric acid and nitric acid are used as base reactants to react with the surface oxide of a high-temperature alloy, and the hydrogen peroxide is used as a catalyst to accelerate the generation of the reaction. The chemical pickling solution provided by the invention is obvious in pickling effect and high in efficiency, the treated high-temperature alloy has a bright and uniform surface; the pickling solution is low in heat release in the matching process, no inflammable, sensitizing and explosive reactant is generated, and the security is high.

Description

technical field [0001] The invention relates to a chemical pickling liquid for removing a surface oxide layer of a superalloy containing Cr and Al elements and its application, and belongs to the technical field of removing an oxide layer by a chemical method of a superalloy. Background technique [0002] In nickel-based, iron-based and cobalt-based superalloys, in order to improve the oxidation resistance and corrosion resistance of the alloy, a certain amount of Cr element is often added to the alloy to form a good adhesion and dense Cr 2 o 3 type oxide film. At the same time, solid solution and precipitation strengthening elements Ni, Al, etc. of the alloy will also form NiO, Al 2 o 3 Oxide film. The complex alloying elements make the superalloy oxide film have the characteristics of multi-layer and multi-phase, and the outer layer is composed of Cr 2 o 3 Mainly, the inner layer is Al 2 o 3 Mainly. Although this greatly improves the oxidation resistance and corro...

AI Technical Summary

Problems solved by technology

For example, when preparing pickling liquid, especially when using sulfuric acid, there is a risk of a large amount of exothermic heat, and the use of hexamethylenetetramine increases the risk of flammability, sensitization and explosive reactants

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