Regarding the corrosion of metals by hydrochloric acid
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The submersed support at the end of the mixing shaft of the company’s mixer is made of 316 stainless steel; it is occasionally exposed to hydrochloric acid, with a concentration of up to 32%, although this level is not actually reached due to the mixing in with other domestic wastewater. The exposure time is less than 12 hours, and there is a pH meter that triggers the addition of alkali for neutralization and water for dilution whenever a low pH is detected. This happens only a few times a year. Therefore, I would like to ask whether it is necessary to replace the material immediately, and what metals are more resistant to hydrochloric acid and can be welded to carbon steel more easily. I also want to ask about the corrosion rate of 316 stainless steel in hydrochloric acid at a certain concentration.
It will corrode 316. May I ask, what is the reaction temperature? Was stirring used for surface anti-corrosion?
At room temperature, the stirring liner is plastic; only the area where it connects to the support base is made of stainless steel. Corrosion will definitely occur, but it’s not clear how fast it will happen, or whether it’s necessary to replace the material immediately. The shaft is a tube with a diameter of 76; in fact, the contact time is very short – probably just a few hours over the course of a year. The concentration is also not high, at most 10%.
If possible, add me on QQ at 2328276632 and send me a picture so I can help you determine what anti-corrosion measures to use. By the way, how is the lining usage?
Stainless steel is certainly vulnerable to such operating conditions; there’s no room for taking chances. Just as an idea, what about using alloy steel with nickel-phosphorus plating and sealing treatment? It offers good corrosion and erosion resistance
It’s mainly the stainless steel used for ground support – your company really is being cheap there. I suggest using a frame with two supports to eliminate the need for ground support; otherwise, it’s quite difficult for any material, whether it’s 316 or another type, to resist hydrochloric acid.
Corrosion rate of 316L in hydrochloric acid (g/m2·hr): at 80°C, 1% concentration: 2.45; 3% concentration: 6.66; 5% concentration: 13.6 ————————Nanguan Metal