Base Metal Groupings

Date 10-29-2008 17:20

I'm using AWS D1.1, 2008. My latest PQR required a tensile test, which I outsourced to a lab. I decided to compare my test coupon's Tensile Range results against those of the Code's (the value's given in Table 3.1, Pre-qualified Base Metal).

My metal, ASTM A513, wasn't listed. The closest metal listed in D1.1's Table is ASTM A516. I looked at my material certifications and compared it against the lab's values.

The material certifications are for what that actual batch of material was. I'm wondering what are the values supposed to be. ASTM has access to a database for $1,000 per year.

Question(s): Is my approach valid? Should I spend the $1,000 for the ASTM information? Are there any sources of this information for free?

I run into this problem frequently while using AWS D1.1, D1.2, D1.3, D1.6, B2.2, and others. They don't offer enough material choices.

Thanks

By swnorris (****)

Date 10-29-2008 19:19 Edited 10-29-2008 19:21

The A516 may be the closest NUMBER to A513, but you can't go by that. Min. yield for A513 is 72,000 psi and min. tensile is 87,000 psi. Just curious.... is the need for a PQR due to A513 not being a prequalified base metal? If so, then A513 wouldn't be shown in Table 3.1 in the first place.

Try this link:

http://www.onlinemetals.com/steelguide.cfm

Also, your material supplier should be able to furnish you with the y & t for the applicable specification.

By Ke1thk

Date 10-29-2008 20:13

Thank you for the link.

I have three reasons for the PQR.
1. Number one is that D1.1's pre-qualified welding procedure's don't apply to GTAW.
2. Number two is the base metal differences.
3. Number three is a new customer that actually reads the welding documents.

That's right. Most of my customer's don't read 'em. In my 25 years of experience I've seen most of my customer's auditors look at the WPS, PQR, and Qualification records for no more than 15 seconds, until now.

I look at this as an opportunity to learn more about welding.

Again, thanks for your help. I need all the help I can get.

By swnorris (****)

Date 10-29-2008 20:32

I agree. Most don't read them because they don't understand what they're reading. It's actually refreshing to find one that does.

If you want to learn more about welding, you're definitely in the right place. The guys on this forum really know their stuff.

By bozaktwo1 (***)

Date 11-03-2008 17:45

I think many of us can relate to #3 on that list.

You know, I have found a lot of value in performing PQRs on even my D1.1 prequalified joints. It instills great confidence in the welder, the QA inspectors, and the PM, and it allows you to develop insight into the process variables which your machines are capable of reproducing. Not all welding machines are created equal!

Meanwhile, good luck, and I agree that this is THE place to go for welding knowledge. Period.

By HgTX

Date 11-04-2008 23:15

As someone else said, A 516 is not "close" to A 513. The ASTM numbers are just names and don't mean anything. A higher number just means the spec was written at a later date.

You can buy individual specs from ASTM for nonshocking costs. ASTM A 513 costs $42:
http://www.astm.org/Standards/A513.htm
and you can download it immediately.

You can also buy books of specs:
http://www.astm.org/BOOKSTORE/BOS/section01.htm
If most of the specs you want are all in one volume, it might be worth your while.

D1.1 has a limited (though still pretty long) list of *prequalified* base metals. For everything else, you can run a PQR--which it looks like you're running anyway.

By Ke1thk

Date 11-05-2008 13:02

Thanks for all the input. This is a great resource. Welding documents now are clearer to me than at any time in the past thanks to your help.

For me, performing the entire process of PQR's, WPS's, and Qualifications is worthwhile. I'd even suggest it as an exercise in preparing for the CWI exam. I learned a lot.

I recall a quote from Investor's Business Daily, "It's easy to plow the fields in your mind. Take action and perform the work for results."