Comparison of corrosion resistance between titanium and duplex stainless steel 2205
Thread Content
Our company previously used titanium for the phosphorus oxide reaction (the reaction between phosphorus trichloride and oxygen to produce phosphorus oxychloride), but it was found that the tube walls suffered severe corrosion. Analysis shows that during maintenance, water vapor entered the reactor, where it reacted with phosphorus oxide to form salts and acids. According to literature, titanium reacts with these salts and acids under certain conditions to produce titanium tetrachloride. I would like to use duplex stainless steel at present; I’m not sure if that’s possible. Could someone please give me some guidance?
For such problems, the first step should be to consider preventing the entry of moisture from a process perspective, as it is difficult to quantify the amount of salt acid due to the influence of these unintended factors. From the perspective of material selection, duplex steel is likely not a good choice; nickel-based alloys of the Ni-Cr-Mo series could be considered, although corrosion coupon tests are the most reliable method
Thank you! You’re absolutely right; at this stage, salts or acidic substances are inevitable. We are working on improvements, but to ensure safety, it’s still necessary to choose materials carefully.