Chloride ion content and material selection principles
Thread Content
Dear heroes, is there any necessary relationship between the content of chloride ions and the selection principle of materials? Is there any specific standard? Because we also make some wastewater treatment equipment, the components in wastewater are more complex. What is the most cost-effective material that is resistant to chloride ions? Thanks!
Personally, I think duplex steel is the better material.
However, the price of dual-phase steel is too high and ordinary enterprises cannot accept it.
The chloride ion content is of course related to the material selection, and has a great influence. Generally, good materials are expensive. I wonder if some additives can be added to alleviate the impact of chloride ions? You can go to the water treatment area and ask about this question. They are more professional in this area.
For wastewater treatment equipment that has certain requirements for chloride ion corrosion, the materials used will of course consider cost-effectiveness. There are many materials that are resistant to chloride ion corrosion, but if you consider the price factor, if the chloride ion concentration is less than 1000ppm, you can consider 304 stainless steel, but it has pitting problems. If the concentration is higher, 316L is recommended, and there will also be stress corrosion problems. However, if it is general wastewater, it can be used； If you are more corrosion-resistant, you can choose duplex steel, or aluminum brass, navy copper, nickel-nickel copper, titanium, etc., but generally you will not be willing to spend so much money. ； There are many discussions on the Internet about the selection of materials resistant to chloride ion corrosion. You can search it.
Our factory makes heat exchangers, and many projects have strict requirements on chloride ion corrosion. The commonly used 316L pipes have good chloride ion corrosion resistance, the price is generally acceptable, and the heat exchange effect is also relatively good, haha
The chloride ion corrosion resistance of titanium tubes is better than that of 316L, but the price is very expensive. However, the wall thickness of the tubes can be chosen to be thinner. Although the thermal conductivity is relatively low, the heat transfer effect is better than that of 316L.
Can be referenced http://www.thermol.com/phedata.htm
Generally, metal chloride-resistant pipes are more expensive. If the wastewater temperature is not high, below 80 degrees, non-metallic materials can be used, which are much more cost-effective than metal materials.
Generally speaking, 316L is used for chloride ions above 80ML, but it can also corrode titanium plates.
Is it possible to perform pre-treatment to neutralize the chloride ions first?
Chloride ion content 60℃ 80℃ 120℃ 130℃ = 10 ppm 304 304 304 316 = 25 ppm 304 304 316 316 = 50 ppm 304 316 316 Ti = 80 ppm 316 316 316 Ti = 150 ppm 316 316 Ti Ti = 300 ppm 316 Ti Ti Ti > 300 ppm Ti Ti Ti Ti
Received, high, it’s a pity that I can’t give you extra points
If it is a container, it can also be made of carbon steel with a fiberglass coating inside. This type of container has better resistance to chloride ions and is cheaper.