Formulas for Tensile and Yield strength

[plsonline]

Can anyone help with how to cross check the values given in a material cert. In the back of my head there is a formula but can not recall what it is for...

I remember you share the tensile strength by the yield strength but this dose not give the value I am looking for.

 

[metengr]

The values are stated for each. You don't need a formula.

 

[EdStainless]

It is simply load/area for the test sample, there is no way to calculate it, it is measured.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube

 

[Maui]

Are you asking for a mathematical relationship between the tensile strength and the yield strength?

 

[plsonline]

Thank you for all your replies, I have remembered the formulas to cross check the values for Rm, Re and %A when cross checking a
material cert. However dose anyone know how to validate a STRA EL% when only the percentage value is shown on a cert.

Try these your self

Re/Rm = %A Re/%A = Rm %A*Rm = Re

these really do work

 

[FennLane]

This all sounds a little strange and I have never heard anything like this in more than 40 years working as a Metallurgist 30 of which were spent making testing machines.

Strain and elongation are essentially dimensionless so what do you mean by 'validate them'?

Sounds like a Bulgarian Constant to me.

 

[EdStainless]

Yes, they don't work. For some materials they happen to be fairly close but for most metals they are way off.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube

 

[saplanti]

If you have the material certificate and the related code(s) you do not need anything else to check I guess.

 

[mrfailure]

Tensile strength, yield strength, and elongation really do not have such a numerical relationship that can be applied. Some people have tried to relate tensile strength to yield strength as a rule of thumb, but these relationships really vary due to processing including heat treatment. I do have customers who ask for a cross-check of results by having another sample from the same heat/melt tested. It is also perfectly valid to ask the lab to recheck the raw data used to generated tensile results to make sure there were no issues looking at the stress-strain curves or to make sure cross-section was not input correctly. Elongation is a manual measurement that can always be rechecked on the tensile specimen.