Electrochemical Characteristics of Alloy 182 Weld and Low Alloy Steel in High Temperature and High Pressure Water from 25°C to 288°C

Abstract

This study was carried out to clarify the electrochemical characteristics of Alloy 182 Weld and Low Alloy Steel in high temperature and high pressure water from 25°C to 288°C. The specimen was obtained from Alloy 182 overlaid weld and low alloy steel. Corrosion potential of each metals and galvanic current between the metals in 5.0×10⁻³ M H₂SO₄ and 4.5×10⁻³ M Na₂SO₄ aqueous solution were measured in an autoclave. The temperature of the autoclave was raised from 25°C to 288°C at a rate of 5°C/min. As the results of these tests, temperature range was observed in which alloy 182 has possibility to dissolve, i.e., corrosion potential of Alloy 182 was less noble than low alloy steel between 170°C and 220°C.