scope:

This report evaluates the elevated temperature strength properties of carbon-moly steel, and various modified versions of that steel commonly identified as manganese-molybdenum or manganese-molybdenum-nickel steels. The data that have been evaluated encompass test results previously included in ASTM Data Series DS 6 (1953) ⁽¹⁾ and DS6-S1 (1966) ⁽²⁾, and previously unpublished test results gathered by The Metal Properties Council.

Employing the method of least squares, trend curves depicting in ratio form the characteristic temperature variations of yield and tensile strengths have been developed. The rupture data have been evaluated by both direct isothermal interpolation or extrapolation, and by time-temperature parameters, to establish the temperature dependences of the average and minimum stresses to cause rupture in 1000, 10,000 and 100,000 hours. The secondary creep rate data have been evaluated by direct interpolation or extrapolation to determine the temperature dependences of average and minimum stresses to cause secondary creep rates of 0.1 and 0.01 percent per 1000 hours. These latter trend curves could be developed only for C-Mo steel, there being too few data for the remaining grades to warrant such evaluation. Elongation and reduction of area data are included for both the short time elevated temperature tensile tests and for the rupture tests.

Several summary figures immediately following this abstract, Figs. 1-6, show the temperature dependence of strength properties for the various grades evaluated in this report. In these figures, the yield and tensile strength curves have been computed from the respective ratio trend curves so that they correspond at room temperature to the specified minimum values of common ASTM specifications.

The body of the report provides in tables, text, and figures, details concerning the identification of the individual lots of material, the evaluation procedures, and the results.