Why does material N02201 corrode in high-temperature hydrogen chloride?
Thread Content
The pipe material is N02201, an imported material, and the medium is high-temperature hydrogen chloride at around 600°C. After one year of operation, leaks appeared in multiple areas and the wall thickness thinned significantly. Why did corrosion occur so rapidly? Please ask the forum members for help.
All materials have usage condition restrictions!
Chloride ions, once they have corroded the passivation film, cause penetrating corrosion damage to stainless steel. This is the understanding!
I understand what you mean, but the material I use isn’t stainless steel either. Furthermore, can chloride ions be present in hydrogen chloride gas at 600°C?
I just want to know what material is suitable for this type of operating condition.
Chloride ions will be present, but in very small amounts; meanwhile, you need to ensure that there is no oxygen present.
If it’s just high-temperature hydrogen chloride, it certainly won’t cause corrosion; there must be water vapor present. If the operating conditions cannot be resolved, it is recommended to upgrade to titanium material.
Under normal operating conditions, the corrosivity of the medium is very low, but significant corrosion occurs during startup and shutdown.
In other words, the moisture level cannot be guaranteed during starting and stopping; find a solution – this material isn’t cheap either
Water and corrosion protection is crucial during startup and shutdown! Once it occurs and leads to CL-, the consequences are quite serious!
It is simply impossible to have a large amount of water in the system; the water content in the materials is below 50 ppm. The key issue is how to prevent corrosion, and at present there is no effective solution for this.