Anti-corrosion methods and protective effects in the weld area of stainless steel pipes

Stainless steel is a material with good resistance to seawater corrosion and is widely used in marine engineering. However, in practical engineering applications, stainless steel connection parts, especially welding areas, often suffer from various corrosion damage, causing great losses. Therefore, this article conducts comprehensive experimental analysis and research on the seawater corrosion and anti-corrosion mechanisms of stainless steel welds based on the seawater corrosion characteristics of stainless steel.

First, experimental research was conducted on the chemical composition, non-metallic inclusions and metallographic structure of the stainless steel tube welding area (weld, heat affected zone, base metal), intergranular precipitation phase (σ phase) grain size, etc., and at the same time, through Measurement experiments of polarization curves and AC impedance spectra verified the existence of corroded microbatteries and derived the mechanism of local corrosion. Then, experimental research was conducted on the important factors that affect the corrosion resistance of stainless steel to seawater, such as seawater concentration, welding process and other factors. Through experimental analysis, it was found that after adopting the new welding process, the microstructural properties of the weld area are improved, and the corrosion resistance is greatly improved. In addition, the salinity of seawater is about 3%, and the corrosion rate of stainless steel pipe welds is the largest.

Secondly, the anti-corrosion methods and protective effects of stainless steel pipe welds were studied. First, an experimental study of cathodic protection with impressed current was conducted on uncoated bare steel, and the protective potentials of different areas of the weld were obtained. After applying cathodic protection, the corrosion of the stainless steel weld was significantly reduced; then, the coating protection and cathodic protection were combined The protective effect of the protection was experimentally studied, and the optimal protection potential range for joint protection was obtained. The corrosion current density and degree of protection under the optimal protection potential were calculated. Compared with adding anti-corrosion coating alone, the corrosion rate was It is greatly reduced, which shows that the joint protection technology has a better protective effect on corrosion resistance of stainless steel.

Metallographic Test – Metallography Testing
Metallographic Test Report
Stress Corrosion Cracking (SCC)
Chloride Stress Corrosion Cracking
Stainless Steel Corrosion
Corrosion of Piping
Corrosion Process
Surface Coatings for Corrosion
Corrosion Resistant Material
Bi- Metallic Corrosion.Galvanic Corrosion
Intergranular Corrosion
Intergranular Corrosion of Stainless Steel Tubes
Corrosion Resistant Stainless Steel Tube
Corrosion Resistance of Stainless Steel Tubes
Seawater Resistance of Stainless Steel Tubes
Corrosion Mechanism in Stainless Steel Tube
ASTM A262 Intergranular Corrosion Test IGC
ASTM E112 Standard Test Methods for Determining Average Grain Size
Methods of minimizing chloride stress corrosion cracking

Anti-corrosion methods and protective effects in the weld area of stainless steel pipes

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