53 / 2024-09-18 16:20:51

The Corrosion Behavior of HVOF Inconel 625 Coating in the Simulated High Temperature and Strong Corrosive Environment

High velocity oxy fuel (HVOF),Inconel 625 Coating,Accelerated corrosion,Yellow phosphorus tail gas,Corrosion

Yellow phosphorus tail gas is rich in CO with a very high calorific value. However, it contains corrosive impurities such as sulfur and phosphorus even after water washing treatment, which can lead to rapid corrosion failure of the boiler. Using high velocity oxy fuel (HVOF) spraying Inconel 625 coating on the boiler is a highly feasible solution. In this paper, electrochemical corrosion tests and high-temperature acid mist accelerated corrosion tests were conducted to simulate the corrosion performance of yellow phosphorus tail gas under environmental conditions. It was found that HVOF Inconel 625 coating revealed high hardness, low porosity and excellent corrosion resistance. In the corrosive environment simulating yellow phosphorus tail gas, significant failure corrosion only occurred on the surface of the samples 72 hours later. The surface corrosion product layer presented a two-layer structure, with high concentrations of Cr₂S₃, Ni₃S₂, NiS, and Ni₉S₈ on the surface, and phosphate based corrosion products on the inner layer. This work had preliminarily verified that the Inconel 625 coating prepared by HVOF met the basic requirements for use in yellow phosphorus tail gas boilers.