Development and Application of Highly Anti-Corrosive Stainless Steels: Case Study of the Seoul Waterworks System

This research investigated the primary reasons for corrosion of the seven kinds of stainless steel, STS 254SMO, STS 2205, STS 304, STS 316L, STS 329LD, STS 444, and STS 470FC in the water treatment plants(WTP), the water reservoirs(WR), and the soil for 12 months. In the water treatments and water reservoirs, condensed water was formed on the specimens where the pH and maximum Cl were analyzed by 2.1 and 415 mg/L. STS304 and 316L were corroded respectively from the base metal specimens. A welded STS specimens were corroded with pickling((10% HNO3+3%HF), but not corroded with pickling(15% HNO3+6%HF). From the soil corrosion test, the pipe to soil potential showed a fall with a high concentration of chloride ions and sulfate ions in the soil rather than stray current from subways.