MATERIAL PROPERTY CHANGES OF MAIN STEAM PIPING AFTER 21 YEARS' OPERATION

摘要

In April 1998, main steam piping made of 10CrMo910 steel in power plant which has been operating at elevated temperature for more than 100,000 hours was inspected and evaluated. In this paper, 117 hardness values were analyzed statistically. Results of Charpy impact test for base material and weld of main steam piping were compared with those of new pipe, including impact toughness and brittle-ductile transition temperature of materials. The influence of long-term service at high temperature on the transition temperature of materials was also discussed.