The fundamentals of the true stress-strain tension test, the methods used and the general relationships obtained were discussed in Part I of this paper. In addition the effects of such mechanical conditions, as high and low testing temperatures, the speed of testing, and the proportions of the test bar on true stress-strain values, were described.
In Part II, the effects of various metallurgical conditions on the true stress-strain properties will be reported together with a description of the use of this form of test in connection with the metal forming processes and other materials testing problems.
VII. THE EFFECTS OF SOME METALLURGICAL CONDITIONS AS REVEALED BY TRUE STRESS AND STRAIN VALUES.
The true stress-strain tension test is particularly well suited to bring out the effects of different metallurgical conditions on fundamental material properties. It is proposed here to discuss the effects of such conditions as heat-treatment, alloying additions, cold work, overheating, directionality, etc., on the true stress-strain values.
Heat-Treatment.
The general effect of heat-treatment by quenching and tempering a carbon steel on the true stress-strain properties is illustrated in Figs. O -O "It to I8 inclusive. These results were obtained u on uniform .~