Abstract
Study of the mechanical properties, including creep, and of the welding and fabrication characteristics of steel containing 0.5 per cent chromium and 0.5 per cent molybdenum, designed for elevated-temperature service, has shown this grade to be essentially similar to 0.5 per cent molybdenum steel without chromium. However, elevated-temperature exposure tests have shown the steel whether deoxidized with aluminum or not, to be resistant to graphitization in butt-welded pipe as well as bead-weld tests lasting up to 15,000 hr at 1025 F and 12,000 hr at 1100 F. Scaling tests and hardness and notch-impact tests before and after air exposure at elevated temperature have indicated that only slight oxidation and little or no embrittlement may be anticipated during service of this grade of steel.
