The Effects of Varied Hydrogen Chloride Gas Concentrations on Corrosion Rates of Commercial Tube Alloys under Simulated Environment of WTE Facilities

摘要

In order to clarify the effects of HCl concentrations on corrosion rates of commercial tubing in Waste-to-Energy (WTE) boilers, a corrosion test was made by altering the HCl concentration from 0 to 1000ppm, together with simulated flue gas composition. Three commercial tubing SA178A, SA213 T11 and NSSER-4 samples were investigated under a well controlled thermal gradient where the gas temperature was at 700℃ and metal temperatures ranged from 480 to 580℃. The duration of each test was 100 hours. The post-test analyses included observations of surface morphology and elementary composition analysis of corrosion products by scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS). The corrosion rates were acquired by measuring the mass loss of samples after the test.rnThe results showed that the addition of HCl to the flue gas increased the corrosion rates of test samples, but the relation between the HCl concentration and corrosion rate was not linear. The HCl effects on corrosion rates were more prominent when its concentration changed from 0 to 500ppm. In addition, the HCl effects were promoted by the increase of metal temperature inrnparticular when metal temperature was over 560℃.