Hardness from Tempering

[MarkUMSU]

I was looking at some metals on MatWeb and saw several examples where different tempers seem to change the hardness, yield, and ultimate strength, but the elastic modulous appears the same.

I'm baffled by how this could be possible unless the data is in error.

Does anyone have a better explanation?

 

[swall]

The data is correct. Elastic modulus is an inherent physical
property of the material and is not changed by heat treating or mechanical working.

 

[prost]

Would you say that a good way to think of it is that the elastic properties of an alloy aren't changed by tempering, bu the inelastic properties of an alloy are changed by tempering?

 

[TVP]

MarkUMSU,

Did you take a University class in materials? Did you keep the textbook? Read the section on bonding and how it relates to elastic properties.

 

[eromlignod]

Remember that strength has nothing to do with stiffness. Strength is the point at which a material fails and is unrelated to how far a material deflects under load.

So, for example, if you cantiliver the end of a steel bar out and put a weight on it, it will deflect the same amount regardless of its tensile strength, or usually even its alloy. A bar which has had improvements in its strength by cold work or heat treatment can be bent *farther* before it yields or breaks, but still requires the same amount of weight to deflect it a given amount. That's why beam deflection formulas don't include strength.

Don
Kansas City