For wastewater at 80°C with a chloride ion content of 2%, what material is suitable for the heat exchanger?
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Chloride content of 2%; 304, 316L, 2205, or other materials – what is the level of corrosion? What is the annual corrosion rate in millimeters? Which material is the most suitable?
Are there any papers I can refer to? What is the approximate annual corrosion rate of 316L, in mm?
Use as base material for weld corrosion testing!
20,000 ppm of chlorine, 80°C. 304 and 316L won’t work, nor will duplex steel 2205. The main reference standard is GB50050-2017; it requires that for stainless steel, chloride ions at a concentration of 700 ppm should be considered in the case of graphite heat exchangers.
Thank you. According to this standard, the project originally used graphite heat exchangers; however, due to the difficulty in cleaning them, shell-and-tube types were chosen instead
Could you provide some specific sources for the data, such as the annual corrosion rate, along with relevant standards or papers? I need evidence-based information
Wastewater with a chloride ion content of 2% has a corrosivity roughly equivalent to that of seawater. At a temperature of 80°C, and when an online pH detector is used for wastewater neutralization and the system operates reliably without acid present, suitable materials include 254SMO and aluminum-magnesium alloys; for those who can afford it, titanium can also be used； If acidity may be present, nickel-based alloys such as 625 or C276 should be chosen. 904L and duplex steel 2205 are suitable at room temperature; however, their corrosion rate is somewhat high at 80°C, making them less suitable for that temperature.
Two \"Material selection charts for chloride corrosion environments\" are uploaded for reference.