High-Temperature Properties of Cast and Wrought Carbon Steels From Large Valves for High-Temperature Service

Abstract

Abstract The authors report on a comparison made at temperatures of 750, 850, and 950 F of the short-time tension, impact, and creep properties of two forged and two cast carbon steels taken from finished valve bodies and tees obtained from the regular commercial run of three reputable manufacturers and made for service at elevated temperatures. Each manufacturer suppling the material gave it the heat-treatment normally used in his own plant for that particular type of material. Two cast steels and one forged steel contained about 0.35 per cent carbon and one forged steel contained about 0.27 per cent carbon. Definite differences in structure were found. One cast steel as supplied by the manufacturer showed a spheroidized structure, while the other three steels were pearlitic. Results of the creep tests are compared with the structures, and results of the short-time tension tests and impact tests at room and elevated temperatures are given.