Method for spraying and preparing high temperature sulfidation resistant alloy layer on the surface of cast iron

Abstract

The invention belongs to the technical field of metal surface spray and provides a method for spraying and preparing a high temperature sulfidation resistant alloy layer on the surface of cast iron. The method includes the following steps of: (1) pre-treating the surface of a cast iron workpiece before spraying, and exposing the clean and coarsening metal surface of the workpiece; (2) adopting a subsonic speed oxyacetylene flame hot spray method to spray prime coat on the surface of the cast iron workpiece, wherein the prime coat adopts nickel aluminum compound powder; and (3) adopting a high speed arc wire spray method to spray an FeCrAl working layer on the surface of the cast iron workpiece. The technique of the invention is characterized by simple and convenient operation and strong applicability, can save high alloy material and is convenient for promotion and use. Compared with the overall high temperature sulfidation resistant material, the cast iron part prepared by means of the method is low in cost, has excellent resistance to high temperature sulfidation and favorable wearing resistance, and can strikingly improve the service life of the cast iron part in a high temperature sulfidation environment.

Description

Technical field:

[0001] The invention belongs to the technical field of metal surface spraying, and in particular relates to a method for preparing a high-temperature vulcanization-resistant alloy layer by spraying the surface of cast iron. Background technique:

[0002] High-temperature vulcanization of iron-based materials (including steel and cast iron) is a type of high-temperature corrosion commonly found in oil refining, petrochemical, thermal power generation, coal gasification and liquefaction, and various combustion furnaces. Whether in sulfur vapor or in H 2 S-H 2 In a mixed atmosphere, iron-based alloys have poor resistance to high-temperature sulfidation corrosion, and it is urgent to improve the high-temperature sulfidation resistance of the surface of iron-based materials.

[0003] to produce CS 2 Chemical gasification reactor as an example. The furnace body in the furnace is made of gray cast iron, and it is a split structure, that is, a cage structure. I...