Work

Preparation of Ni-P Composite Coatings and Study on the Corrosion Resistance and Antifouling Properties in Low-Temperature Flue Gas Environment

Year: 2025

Type: article

Abstract: In industrial production, flue gas heat exchangers are often affected by the low-temperature condensation of industrial flue gas due to the influence of the working environment, resulting in serious ash deposition and corrosion. In order to solve this problem, in this study, we developed an ash deposition and corrosion monitoring system to compare the ash deposition prevention performance and corrosion resistance of different materials, as well as its influence on the heat transfer performance of different materials in the same environment. The following coatings were selected for the experiment (values in parentheses are the concentrations of the added compounds): ND, Q235, 316L, Ni-Cu (0.4 g/L)-P, Ni-P-SiO2 (40 g/L), Ni-Cu (0.4 g/L)-P-SiO2 (20 g/L), Ni-Cu (0.4 g/L)-P-SiO2 (40 g/L), and Ni-Cu (0.4 g/L)-P-SiO2 (60 g/L). The results show that the Ni-Cu (0.4 g/L)-P-SiO2 (40 g/L) coating has excellent corrosion resistance, while the Ni-Cu (0.4 g/L)-P-SiO2 (60 g/L) coating shows excellent antifouling performance. Through the comparative analysis of polarization curves, impedance spectra, and coupled corrosion experiments, the test materials were ranked as follows based on their corrosion resistance: 316L > Ni-Cu-P-SiO2 (40 g/L) > Ni-Cu-P-SiO2 (20 g/L) > Ni-P-SiO2 > Ni-Cu-P-SiO2 (60 g/L) > Ni-Cu-P > ND > Q235. It was also demonstrated that the new coated pipes were able to reduce the exhaust temperature below the dew point and maximize the recovery of energy from the exhaust gas. The acid–ash coupling mechanism of the coating in the flue gas environment was further analyzed, and an acid–ash coupling model based on Cu and SiO2 is proposed. This model analyzes the effect of the coating under the acid–ash coupling mechanism. Using coated tubes in heat exchangers helps to recover waste heat from coal-fired boilers, enhance heat exchange efficiency, extend the service life of heat exchangers, and reduce costs.

Source: Materials

DOI: 10.3390/ma18173939

Authors: Changqi Lv, Shengxian Cao, Bo Zhao, Xingdong Yu

Institution: Northeast Electric Power University

Language: English

Topic: Electrodeposition and Electroless Coatings

Subfield: Electrical and Electronic Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $3,137

Funder: Jilin Scientific and Technological Development Program