1. The acid resistance of 304 316 and 316L stainless steel wire cloth in phosphoric acid:
In general, in pure phosphoric acid without impurities, commonly used stainless steel can solve corrosion problems.
For example, in some production processes, 304(18-8, Cr-Ni) stainless steel can be used to store 85% cold phosphoric acid and treat 5% cold phosphoric acid, it is satisfying.
316 stainless steel has better corrosion resistance than 304. And if the content of fluorine is not too high, 316-type stainless steel can be used to store and produce fluorine. When a phosphoric acid concentration of 85%, 316-type stainless steel should be under 100℃ temperature.
Mo content in 316L stainless steel is about 2%-3%, it has better corrosion resistance, and with the increasing of Mo contents, the phosphate-resistant performance becomes better.
But in the production of wet phosphoric acid, the phosphoric acid usually contains more impurities, like F-、Cl- 、SO42-、Fe3+、Al3+、Mg2+, etc. Among them, except Fe3+, others accelerate the corrosion of stainless steel, especially F-、Cl- more intensely. In order to improve the stainless steel corrosion resistance in phosphoric acid, increasing the content of Cr and Mo in stainless steel will be more obvious, and Cr has the most significant effect. The effect of Mo is only effective when the amount of Cr in the steel is low (for example, 20% to 21%); when Cr and Mo are high, the effect of Ni in the steel is not significant, so if possible, we may try 443 or 444 stainless steel.
2. The acid resistance of 304 316 and 316L stainless steel wire cloth in sulfuric acid:
When the sulfuric acid concentration of 80% or more at room temperature, you can use 304-type stainless steel.
If sulfuric acid can be inflated, and if the temperature is up to 50℃, can use the 316 type stainless steel and the concentration of 10% sulfuric acid in contact.
If in an air-free solution, the corrosiveness is even greater, if the temperature is up to 65℃, Sulfuric acid concentration of 5%, you can use 317 stainless steel.
If there are other materials in the solution, it is possible to significantly improve the corrosion rate.
In the medium concentration of hot solution, as long as there are 500-2000PPm of copper ions, we can use 304 stainless steel.
The effect of other additives may be reversed. We can use contain Mo, Cu, and Si stainless steel, such as stainless steel 316L.
In summary, the acid and corrosion resistance of 304, 316, and 316L stainless steel wire mesh in turn enhanced.
MAISHI Mfg-Best Partner of Mesh
Any need for stainless steel wire cloth, welcome to send inquiry to MAISHI team to get more technical support.
Leave a Comment