The figures in this SAE Information Report illustrate the principle that, regardless of composition, steels of the same cross-sectional hardness produced by tempering after through hardening will have approximately the same longitudinal tensile strength at room temperature. Figure 1
The figures in this SAE Information Report illustrate the principle that, regardless of composition, steels of the same cross-sectional hardness produced by tempering after through hardening will have approximately the same longitudinal tensile strength at room temperature. Figure 1 shows the relation between hardness and longitudinal tensile strength of 0.30 to 0.50% carbon steels in the fully hardened and tempered, as rolled, normalized, and annealed conditions. Figure 2 showing the relation between longitudinal tensile strength and yield strength, and Figure 3 illustrating longitudinal tensile strength versus reduction of area, are typical of steels in the quenched and tempered condition. Figure 3 shows the direct relationship between ductility and hardness and illustrates the fact that the reduction of area decreases as hardness increases, and that, for a given hardness, the reduction of area is generally higher for alloy steels than for plain carbon steels. It is evident from these curves that steels of the same cross-sectional hardness have about the same strength characteristics, so that any one of several different compositions would yield