Yield Strength and Hardness | ||||||||
The claim is that yield strength and hardness measure more or less the same property of metals: the onset of plastic deformation. | ||||||||
Here is the "proof". A series of real measurement taken from some more or less randomly selected publication about some steels. | ||||||||
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The relevant data are:
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If we look very close, hardness is not just related to the yield stress YS but also to the ultimate tensile strength (UTS); the correspondence might even a bit better than to the yield strength. | ||||||||
It doesn't matter much, however. As long as the relation between UTS and yield strength is roughly constant (as in the picture above), a hardness measurement is good enough. If it's not, you simply can't describe the material very well with just giving single numbers. | ||||||||
3.3.1 What, Exactly is Measured by Hardness?
3.1.4 A Bit More About Tensile Testing
© H. Föll (Iron, Steel and Swords script)