Following is tabulated data that were gathered from a series of Charpy impact tests on a tempered 4140 steel alloy.

(a) Plot the data as impact energy versus temperature.
(b) Determine a ductile-to-brittle transition temperature as that temperature corresponding to the average of the maximum and minimum impact energies.
(c) Determine a ductile-to-brittle transition temperature as that temperature at which the impact energy is 70 J.

Transcribed Image Text:

Temperature (°C) 100 75 Impact Ernerg 89.3 88.6 87.6 85.4 82.9 78.9 73.1 66.0 59.3 47.9 -65 -75 29.3 27.1 25.0 -175