Please ask experts to recommend chloride-resistant metal materials
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I am facing a serious problem of corrosion of stainless steel by hydrochloric acid during the production of demineralized water. Currently, 304 and 316L grades of stainless steel are being used; the 304 grade is completely resistant to corrosion, while 316L offers better resistance, but corrosion cracks appear at the weld areas. After repairing these cracks, new cracks appear elsewhere. I would appreciate it if experts could offer some guidance, preferably sharing knowledge related to metal materials. Thank you very much!
Is there something wrong with my problem? Why isn’t anyone responding? I’m worried
Do we have to use metal? Some precious metals can withstand hydrochloric acid, such as tantalum, but it’s too expensive. I once used a heat exchanger made of tantalum; it cost several million. Currently, lined pipes are generally used for hydrochloric acid media, while graphite is used in synthesis furnaces. I’m not sure if this will be useful to you?
This post was last edited by Golden Land on 2010-6-1 22:57. Polypropylene or ABS pipes can be used; if metal is not to be used, titanium can be an option.
Our original heat exchanger was also corroded through! Later, everything was replaced with glass-lined material! It seems that carbon steel has a greater resistance to chlorides than stainless steel (according to the data in the manual)!
Titanium can be used. Materials resistant to hydrochloric acid don’t have to be metallic; non-metallic materials work just as well, such as fiberglass.
Reply to 7# pj816: The prices of titanium materials vary depending on whether they are in tube form or sheet form; the price per ton for sheets is around 150,000. Thus, the cost of titanium materials is approximately 4 times that of 304 steel. On the other hand, duplex steel is relatively cheaper. The original poster can search on Baidu. Polytetrafluoroethylene or fiberglass can also be used if the temperature and pressure requirements are not high. Our workshop is facing the same problem, so I pay quite a lot of attention to it.
Austenitic stainless steel is absolutely not suitable, as it will suffer from gravitational corrosion. Carbon steel is also a bit better in hydrochloric acid conditions.
Hastelloy, Monel, Naval Copper C44300, Tantalum. . .
Enameled, rubber-lined, graphite-lined. . . . . . Choose according to your process conditions