Seeking advice on the corrosion of 316L and pure titanium in strongly alkaline solutions
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I would like to ask about the corrosion of 316L and pure titanium in strongly alkaline solutions. Specifically, when the walls of 316L or pure titanium tubes are exposed for an extended period to a NaCl solution at a temperature of 130°C with a pH level greater than 9, will corrosion occur? And if so, is the degree of corrosion severe?
130 degrees temperature. It’s completely possible to use a steel-lined PTFE version! I think this would be great! What is the chloride ion content in the NaCl solution? It is recommended to use steel-lined PTFE!
The chloride ion content requires testing by the production department; the results will be available tomorrow
316L will definitely not be completely corroded in the solution you mentioned within 2 months; I have already tested this. 316L can only be used with moderate acidity or alkalinity under limited conditions. Pure titanium performs only moderately well in strong acids and strong bases, and it is generally difficult to find genuine pure titanium. The cost of using 316L and pure titanium is much higher than that of steel-lined PTFE, yet their service life is by no means inferior to that of the latter two materials; I object to your use of steel-lined PTFE
There are a few questions here: 1. What is the chloride ion content? 2. PH=9 is a weak base, not a strong base. Please check and explain the specific operating conditions before I can reply. Incidentally, in alkaline solutions, the effect of chloride ions on pitting of 316L stainless steel is much smaller. However, 316L stainless steel cannot be used in sodium hydroxide solutions of most concentrations at temperatures above 100°C, as stress corrosion cracking will occur. Pure titanium is prone to hydrogen embrittlement at 130°C in 50% NaOH.