Comparative High-temperature Properties of British and American Steels

Abstract

Some rather substantial differences are found in creep data on similar steels published in various countries. In view of the importance of these differences in relation to design stresses, arrangements were made for an exchange of specimens between The Timken Roller Bearing Co., of Ohio, and The United Steel Companies in order to determine whether the results from the two laboratories, on the same steel, would be in agreement, and to compare the creep resistance of selected steels. Five representative high-temperature steels were chosen comprising three commonly used ferritic steels and two austenitic steels. For each composition, four creep curves were obtained, two by each laboratory. Stress, temperature, and time adopted in the tests in the two laboratories were the same and no attempt was made at standardization of test procedure. A high degree of reproducibility was shown by the test results for the two laboratories on the ferritic steels but those on the austenitic steels showed generally substantial differences. Only two British steels, both of ferritic type, showed similar creep behaviour compared with the corresponding American steels, the remaining three steels showing appreciable differences, which are discussed.