Steel Grouping classification

Date 11-02-2007 13:18

Grade A-Group 1; Grade E-Group 2; Grades F & H- Group 3; Grade B-Group 4; Grades C, J, K, S, & T - Group 6; Grade P-Group 8; Grade Q-Group 9; Grade M-Group 10; Grade R-Group12. Hope this helps. From AWS B2.1-BMG:2005

By pax23

Date 11-02-2007 13:31

A 514 is considered a nonprequalified base metal according to D1.1.

It does, however, show up in Table 4.9 (2006 ref) where matching filler metal and preheat requirements are given. Since it is not prequalified, you will have to run a PQR to establish a WPS.

By Bryan Bidewell (*)

Date 11-02-2007 14:41

If it is the relevant grade to put it into groups 1 or 2 and I have WPS that qualifies all group 1 and 2 steel, is a PQR and a new WPS required still required?

By pax23

Date 11-02-2007 15:04

Just because it falls into the range of mechanical properties of the Group I or Group II materials does not mean you can categorize it as such.

Only the materials listed in those groups in Table 3.1 are in those groups. Anything not in Table 3.1 is considered either a Table 4.9 material or an unlisted material.

I have to revise my earlier statement. A 514 is not an unlisted material according to D1.1 but rather a Table 4.9 material. This matters greatly when looking at Table 4.8 to determine qualification changes.

Look at Table 4.8. In order to have a WPS that does what you state, it must be supported by a Group II to Group II PQR. A Group II to II qualifies for the following combinations only:
G1 to G1
G1 to G2
G2 to G2

There is no allowance, I see, for a Table 4.9 material.

By rickc

Date 11-02-2007 15:24

As said, 514 is listed in Table 4.9 on Page 144 of the 2006 edition and as such you need to qualify by testing.

Table C-2.4 on page 414 splits 514 into the same thickness/yield strengths as Table 4.9 and call it Groups IV and V. Table 4.8 has been a little thorn in my side though. On one hand it reads that you have to qualify every single grade available of 514 but Note 2 allows the yield strength to be reduced if allowed by the steel specification. They also make it clear in previous editions and the commentary that they intended for 514 to be divided into the two groups based on it's thickness/strength. It almost seems easier to list 514 under it's umbrella 709 grade 100 spec. to bypass that nonsensical "grade" requirement on Table 4.8 for 514. I dunno, but it's been quite the issue for us with our inspectors.

By pax23

Date 11-02-2007 16:04

Good point, but whatever appears in any commentary should be taken with a grain of salt. If it supports whats in the code text then fine, it can sometimes provide clarification or rationale, but if it contradicts whats in the code text then the commentary always loses. A514 is defined as Table 4.9 materials where it matters. How Tables C-2.4 categorize them may provide some insight, but in the end it is irrelevant since the code text has already defined the base material.

Looking at Table 4.8, note 2, it seems to allow me to do the following:

In a PQR I weld Table 4.9 materials: A514 under 2-1/2in 100ksi min yield to same

I can substitute Table 4.9 material A514 over 2-1/2in 90 ksi min yield to same or the material above without requalification.

Not a bad note to have around. I could see where it would be useful. Without that note I have to requalify.

By rickc

Date 11-02-2007 16:32 Edited 11-02-2007 16:36

Yep! I only referenced the commentary to further support their intent and I completely agree with you that I should be able to weld any 2-1/2" and under 514 to any other piece of 2-1/2" or under 514 if I qualified it but, the Table 4.8 row that begins with "Any Table 4.9 steel to same or any other Table 4.9 steel" specifically states that I only qualified "the same material specification, grade/type and minimum yield strength as the Steels listed on the PQR."

It's 514 to 514 so, I'm good on the material specification requirement. Note 2 lets me ignore the minimum yield strength requirement as the reduction of yield strength with increased thickness is allowed by the ASTM-A514 specification. This will allow me to weld thicker sections of 514 if desired. However, the "grade/type" requirement it what's hurting me.

514 grades are largely thickness designations. If I welded a piece of 1" 514 Grade B to 1" 514 Grade B that means that I'm only allowed to weld Grade B which has a maximum thickness of 1-1/4". However, you can't buy the thicker grades in thinner slices. So, if I wanted to weld Grade F (2-1/2" thick) then I'd have to buy it and mill it down to 1" and run another coupon. Ditto for grades A(1-1/4"), E(6"), H(2"), P (6"), Q(6") and S(2-1/2"). Expenses start adding up real quick there. I don't believe that this is AWS' intent and I can point to several instances in the book that seem to support exactly what you've said but, "grade/type" is what's printed on the page.

By pax23

Date 11-02-2007 17:03

True. I did not delve deep enough into the material spec itself. I can see the problem now.

By rickc

Date 11-02-2007 17:56

It's been a real PITA for us. Particularly considering that there's enough overlap for chemical composition in the 514 specification that the grades can really just be thickness indicators. Just glancing at the steel specification I can see that it's possible for a Grade B specimen to be chemically identical to Grade H for the elements listed but, I still have to run a second coupon under a strict reading of Table 4.9.

It's hard to believe that this "grade/type" requirement has been in the code since the 2000 edition and has never been addressed in an errata or an official code interpretation. It makes me wonder if my company is the only one trying to comply with D1.1 while working with 514 sometimes.