Q: I’m using sodium hypochlorite to control slime and bacteria formation in a power plant water system. It’s in about a 15% solution. I tried using Duplex fasteners thinking they are good with chlorides but I’m having corrosion issues. Any suggestions?
A: I think the problem you have is the fact that sodium hypochlorite is a strong oxidizer. Duplex can experience corrosion in chloride solutions where oxidizers are present. In this case, I would suggest either Titanium grade 2 or grade 5 depending on the level of strength you need. Both titanium grades are nearly immune to hypochlorites. Titanium provides excellent resistance to oxidizers because of its stable oxide film, which regenerates almost instantly in the presence of water or oxygen. Both grade 2 or 5 will exhibit these properties. Grade 5 is only necessary if you require higher strength.