Comparison of H 2 S high-temperature corrosion characteristics of three kinds of low-alloy and heat-resistant-steel tubes

Abstract

This study investigates the H₂S high-temperature corrosion characteristics of three common heat – exchanging tubes for supercritical boilers, namely SA-213T12, 15CrMoG and 12Cr1MoVG. The high-temperature corrosion rates and wall thickness reduction rates of these three materials were investigated. The results indicate that the spalling of corrosion fragments produced by high-temperature H₂S corrosion is the main cause for the reduction in the tube wall thickness. Moreover, as a pressure component, the thinning of the water wall tube thickness is an important index to judge its service life. The bulk aggregation of corrosion products can easily cause the corrosion layer to fall off and make the corrosion reaction go inside. By comparison, the abilities of the three kinds of tubes for anti-H₂S high-temperature corrosion are ranked from weak to strong as follows: SA-213T12、15CrMoG and 12Cr1MoVG. Besides, the high-temperature H₂S corrosion process is the most sensitive to temperature.