What material is preferred for pipelines carrying high-temperature ammonium chloride aqueous solutions?
Thread Content
As the title suggests, there is currently a pipeline carrying a high-temperature ammonium chloride aqueous solution, with a CL- concentration of around 30%, a temperature of 135°C, and a pressure of less than 0.5 MPA. I have used 316L, Ti2, and 1105 duplex steel so far, but the results haven’t been very good – there are leaks occurring frequently. Do any of you have any good suggestions? Or a suitable material?
Check where it’s leaking Material leakage indicates that proper protection was not provided during manufacturing! Leakage at the weld indicates a problem with the welding!
Both situations exist; the device itself is also available. Are there any better material options?
This post was last edited by foam_ZPTK on 2019-3-2 14:05. Have TA9 and TA10 tried it?
Try again later; is there any relevant information available?
Corrosion-resistant applications of titanium-palladium alloys (TA9) and titanium-molybdenum-nickel alloys (TA10): The Ti-0.15Pd alloy (TA9) and Ti-0.8Ni-0.3Mo (TA10) are designed as materials resistant to crevice corrosion in high-temperature chloride solutions. Since titanium absorbs hydrogen at 400 degrees and oxygen at 600 degrees, temperature must be taken into consideration during the processing. , various acid solutions ； Such as ； Sulfuric acid, hydrochloric acid, oxalic acid, nitric acid, alkaline solutions, chloride solutions, etc. Crevice corrosion of titanium is a type of localized corrosion that occurs at high temperatures in the presence of chloride ions. The accumulation of chlorides and the formation of local electrochemical cells outside the crevices lead to a decrease in the pH value in those crevices, along with an increase in the concentration of chloride ions. This results in active dissolution at the crevice sites. Therefore, once crevice corrosion starts in titanium, the corrosion proceeds very rapidly, allowing the tube walls or containers to be penetrated in a short period of time. Form holes. The measure to prevent crevice corrosion in equipment is regular cleaning to remove chlorides. Another approach is to adopt a structural design that prevents the accumulation of chlorides such as NaCl. For greater reliability, TA9 and TA10 corrosion-resistant titanium alloys are used; these alloys generally offer much better resistance to chlorides, crevice corrosion, and high-temperature strength than pure titanium, and they demonstrate their superior properties in high-temperature environments. Therefore, TA9 and TA10 have always been the preferred titanium alloys for corrosion resistance and high-temperature tolerance.
T2 should be fine! It’s mainly because the manufacturing process wasn’t properly controlled!
The circulation pipes for the external circulation concentration units we supply to our customers are made of carbon steel lined with graphite, and over the past decade or so, there has been no case of corrosion.
Hastelloy, resistant to chloride corrosion. Lined with polytetrafluoroethylene; resistant to high temperatures and strong corrosion.