higher tensile strength than specified in code

[212197]

for SA 537 class 1 Material, what will be the impact if we get higher UTS than specified in asme sec II 1.?
Generally code indicates minimum UTS required but for SA 537 material, minimum & maximum range of UTS is specified.

 

[EdStainless]

You cant go over the max, if you do then it does not meet SA537cl and can't be certified that way.
I don't recall why there is an upper limit in this case.

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P.E. Metallurgy, consulting work welcomed

 

[gtaw]

Ductility?

Best regards - Al

 

[Ishack]

Ductility could be one of the reason. This limit may be set to effective utilize the grade within the required properties. The same range can be seen in PSL 2of API 5L materials whereas PSL 1 which is least stringent doesn't have such maximum range.

 

[212197]

Sir,

reported ductility (percentage elongation) is meeting the requirements even yield is also meeting the requirements;
only UTS is higher by 25 mpa than the maximum limit specified by code.
i don't have option , what technical justification i should give to client so that it will get accepted by our client through non conformity report.
i cannot buy new material.

 

[gtaw]

There is a loose relationship between ductility and toughness. There is also a relationship between hardness, strength, and ductility. Then there is the specification; it rules. If the material in question does not meet the criteria provided by the specification, it simply doesn't comply. There are often rules included where if a test results falls outside the published limits, a new test can be performed. I suggest an additional test be performed if it is permitted by the material specification cited by the customer. However, I know of no magic wand that allows the vendor to over ride the requirement of the specification.

Steels used for the construction of bridges often include maximum values for the mechanical properties to ensure they perform in service in a predictable manner. The end used that included the material specification in the design, purchase order, or other contract document does not bear a responsibility to the vendor to justify the requirement. The vendor does have a responsibility to proved the materials as specified by the customer.

Best regards - Al

 

[EdStainless]

If the reported strength is above the limit, and a mill certified it to the spec then you need to call their registrar and report that they are generating non-compliant MTRs.
This material does not meet the spec, end of discussion.
My hunch is that it has to do with either how the material ages, or how it responds to some environments.

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P.E. Metallurgy, consulting work welcomed