The issue of combining stainless steel pipes with fiberglass-reinforced plastic
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There is a Φ500 flue pipe made of 304 stainless steel； The temperature inside is between 40 and 50 degrees, and the flue gas is an acidic medium; it suffered corrosion and perforation after just a few months of use ； The proposed solution is to apply vinyl fiberglass-reinforced plastic coating to the outer surface of the stainless steel pipes. The question is whether this solution is appropriate Can stainless steel and fiberglass-reinforced plastic be combined? Could the anti-corrosion layer separate from the pipe after a few months of use, leading to leaks?
Since the temperature is not high, it is recommended to use carbon steel glass-lined pipes or steel pipes lined with rubber.
This post was last edited by Wang Wei2 on 2021-9-11 at 16:00. This type of corrosion is referred to in our industry as low-temperature wet flue gas corrosion, that is, corrosion caused by the dew point of the flue gas. This type of corrosion affects carbon steel, as ordinary stainless steels do not have good corrosion resistance. That’s because applying resin fiberglass directly onto the stainless steel surface does not yield good results. There are two reasons: first, the adhesion between stainless steel and fiberglass-reinforced plastic is very poor, resulting in no good interlayer bonding ； Secondly, the physical thermal expansion coefficient of the thicker fiberglass layer is different from that of stainless steel, resulting in significant internal stress. Therefore, under the influence of these two factors, fiberglass reinforced plastic and metal will delaminate. If glass fiber reinforced plastic is indeed to be applied to the surface of the pipe, the issue of the transition bonding layer between the stainless steel layer and the glass fiber reinforced plastic layer can be addressed first, which will prevent delamination between the stainless steel and the glass fiber reinforced plastic.