An Evaluation of Corrosion Resistant Alloys by Laboratory Corrosion Tests -Development of Corrosion Resistant Superheater Tube, Part 1- (NEDO Project, Development of High Efficiency Waste-to-Energy Plant)

Abstract Laboratory corrosion tests simulating environments of superheater tubes in waste incinerators were conducted to obtain information on the performance of 17 commercial "corrosion resistant" steels and alloys. The steels and alloys were corroded in a simulated flue gas atmosphere containing 1000 ppm HCl -50 ppm SO2 -10% O2 -10% CO2 -20% H2O -bal.N2 at 450 and 550° C for 50 and 100 h. These corrosion tests were conducted at five different laboratories. Four types of corrosive ashes, two tube deposits taken from a stoker-type furnace and a fluidized bed combustor, and two synthetic ashes with different chemistry, were used to simulate the corrosion environments. Corrosion weight-loss measurements as well as microscopic observations were performed to evaluate resistance of steels and alloys not only to general corrosion but also to localized corrosion such as grain boundary attack.