高強度Cu–Sn–Zr系合金による給湯機熱交換器銅管の腐食対策

抄録

Corrosion has been reported to occur in copper tubes of heat exchangers in multiple circulation hot water supply systems. We have been investigating the applicability of high–strength Cu – 0.65 mass% Sn – 0.014 mass% Zr – 0.020 mass% P alloy as a countermeasure material. Field tests were performed and each part of the heat exchanger was examined. Film formation on the heat–affected part was slower than that on the non heat–affected part, but the heat–affected part showed such excellent corrosion resistance as the non heat–affected part by long–term use. In addition, the alloy also suppressed the progress of galvanic corrosion at the brazing part. The alloy is expected to be better than copper as a corrosion–resistant material for heat exchanger tubes.