The high temperature corrosion test body at the time of high temperature corrosion test

摘要

PROBLEM TO BE SOLVED: To perform a corrosion test over a wide high temperature range with a single specimen by applying the constitution that a tubular specimen with a partly thickened cross sectional form is inserted in the heat-transfer tube of an existing plant. ;SOLUTION: The tube inner diameter of a specimen 1 is for example, taken at the same size as the heat-transfer tube of an existing plant where the specimen 1 is jointed. Furthermore, the outline of the specimen 1 is made elliptical, and the minimum wall thickness thereof is made equal to the wall thickness (t) of an existing pipe. Also, the maximum wall thickness is taken at 2t. The specimen 1 is then inserted in an actual boiler as a part of a superheater heat-transfer tube, and a heat conduction analysis is made, using the finite element method. Outer surface temperature even on the same cross section increases with an increase in wall thickness, according to a temperature distribution obtainable from the analysis. A difference in outer surface temperature is 55°C between a minimum wall thickness part and a maximum wall thickness part. Thus, a practical test can be implemented. Furthermore, a corrosion test result at each temperature becomes available by observing the same cross section along the tube outer surface after the test.;COPYRIGHT: (C)1997,JPO