Equivalent diameter in tensile test
Equivalent diameter in tensile test
(OP)
A client has sent us a specification to manufacture 316L tubes (12.7 mm OD) wich indicates the tensile test shall be carried out using a gauge length of 5D, where D is the equivalent diameter. My question is, what does it mean by "equivalent diameter"?
The specimen shall be tested in full cross section.
Thanks
The specimen shall be tested in full cross section.
Thanks
RE: Equivalent diameter in tensile test
RE: Equivalent diameter in tensile test
If the equivalent diameter is related to flow area (cross section?), where does it come from that it is equal to the ID? As far as I understand, the ASTM E8M indicates that the gauge length must be equal to 5D where D is the external diameter.
RE: Equivalent diameter in tensile test
RE: Equivalent diameter in tensile test
In Europe it is more common to use 5D.
I have seen both OD and mean D used in the GL calculation.
At the end of the day it doesn't matter.
Annealed 316L will be up over 50% elong however they measure it.
Strain rate matters more.
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P.E. Metallurgy, consulting work welcomed
RE: Equivalent diameter in tensile test
Is this a structural tube or a fluid-flow ['hydraulic' quality] tube?
Regards, Wil Taylor
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RE: Equivalent diameter in tensile test
Thank you
RE: Equivalent diameter in tensile test
I would use the OD.
And you need to also report the value with a 2" GL in order to comply with A213
= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed
RE: Equivalent diameter in tensile test
Practically, you can use equivalent diameter = (OD+ID)/2. Or, simply use equivalent diameter = OD
Intrinsically, all probably donot matter much, as Ed pointed out, since 316 material would have a large elongation value (unless the deformation rate >95% during manufacturing).
The key is to clarify with the customer.
RE: Equivalent diameter in tensile test