Duplicate Parts for Proof Test (MAWP) UG-101(d)

[DaveZR2]

We are looking to see if it is feasible to substitute a similar material for a proof tested part as described in UG-101

According to UG-101(d)(2)(c), the duplicate part material must: "...have the same or tougher material grouping in UCS-66, Fig. UCS-66, and Notes."

My question is, what is the grouping? Are the materials grouped by the curves A, B, C, D in Fig. UCS-66? If so, which curve is "tougher"? Is A tougher than B, tougher than C, tougher than D?

Further, in UCS-66 SA-516 Grade 70 is listed under Curve B "if not normalized". If normalized it is listed under Curve D. What do they mean by normalized?

Thanks in advance!

Dave

 

[metengr]

The impact exemption curves in Figure UCS-66 are different because of notch toughness behavior as a function of MDMT and material thickness. If you look at each curve and the corresponding MDMT and thickness, you can draw your own conclusion regarding curves that provide lower MDMT impact exemptions.

Normalization is a heat treatment practice to enhance through thickness properties of various materials and to increase notch toughness.

 

[DaveZR2]

I see, thank you. So it's actually the oppposite of what I said. Materials using Curve D are tougher than Curve C, tougher than Curve B, tougher than Curve A.

 

[DaveZR2]

Here is a related follow-up question:

If we were to make a material change from SA-285 C (P-number 1, Group No. 1) to SA-516 70 (P-number 1, Group No. 2), do we need to re-qualify our welding procedure?

Thanks in advance...