Corrosion Resistance Evaluation of Stainless Steel Flexible Pipe with Copper Alloy Joint in Hot Water Environment

Abstract

In order to clarify the applicable conditions as a pipe, in which 80℃ hot water flows, the corrosion resistance of length 500mm or less SUS316L stainless steel flexible pipe with copper alloy joint was evaluated under the conditions simulating an actual environment. The steady corrosion potential Esp was measured during 12 months in the water flow tests keeping a constant value on temperature, residual chlorine concentration, chloride ion concentration and pH. In addition, the localized corrosion potential Vc was measured by a constant potential polarization test.
As a result of these tests, localized corrosion did not be found in SUS316L flexible pipe with copper alloy joint under the condition of temperature 80℃, pH7, residual chlorine concentration 1ppm (target value of water quality management in a water treatment plant), chloride ion concentration 200ppm(standard value of water quality management in a water treatment plant).