AWS D1.1 SMAW prequalified procedure B-U3b

Date 07-30-2009 12:03

I don't believe there is any limit on the electrode dia, since you are writing a new procedure, but you can't take an old procedure that lists a certain size and increase the dia more than 1/32" per Table 4.5(10).

However, I would think hard about using a really large electrode for the root pass, as that groove is kinda narrow and you may not get good penetration at the root, plus if the electrode doesn't fit down in the groove to the root, you will have porosity issues. I would write it to include a smaller dia for the root pass, and step up to the larger dia for the fill and cap passes. I believe you can do this and still remain prequalified unless I'm missing something.

By jwright650 (*****)

Date 07-30-2009 12:08

Another thought....don't forget to MT the rat holes for cracks on those larger sections if that beam falls into a Group 4 or 5 category.

By spots

Date 07-30-2009 12:20 Edited 07-30-2009 12:26

The material is ASTM A 572 grade 50, the client is requiring ultrasound preferably phased array on the completed welds.

Currently I have listed 3/32, 1/8, and 5/32. I was wondering if I should put on 3/16 and 7/32 on the off chance they might be useful in the future.

By jwright650 (*****)

Date 07-30-2009 12:49

Maybe call out for the 1/8 or 5/32 for passes numbered 1-3(or however many passes it works out to fill up and out of the root) and maybe one of the other larger rods for the remaining passes.

By Lawrence (*****)

Date 07-30-2009 16:00

Since you mentioned at the top of the post that you were writing a pre-qualified procedure maybe we should look at Table 3.7 (Maximum Electrode Diameters)

By jwright650 (*****)

Date 07-30-2009 16:03

Good point L....I totally missed looking there.

By motgar

Date 07-30-2009 16:08

spots,

If you are writing a prequalified procedure, then take a look at Table 3.7 (Prequalified WPS requirements). It is on page 71, in the 2006 edition.

There you will see maximum electrode diameter, depending on position and weld type.

As far as the 5/32" electrode: Take a look at what the root opening will be. You want an eletrode that will get deep enough, into the joint. My guess would be that most people used the 1/8" root opening. If you factor in what jwright says about the + 1/32", then you get 5/32." Just my understaning of it.

Hope that helps.

By 803056

Date 07-31-2009 20:36

If you are welding in the flat position and if you are writing a new WPS or revising an existing WPS, consider using an E7028 SMAW electrodes. The electrode is still a low hydrogen electrode, but it can run with AC so it is less prone to arc blow and it has a higher deposition rate than E7018. You will need to store the E7028 in an electrode oven as you would any low hydrogen electrode. Large diameter E7028 are common, whereas large diameter E7018 is less common and arc blow with a large diameter DC electrode is more problematic.

It has been a while, but we used to run 1/4 inch diameter E7028 on a daily basis in one shop I used to work with.

The spacer bar thickness can be increased to 1/4 inch to minimize the likelihood of melting through when you use the larger diameter electrodes, i.e. 5/32 inch or larger.

Best regards - Al

By spots

Date 08-03-2009 17:08

The welds will be made in the horizontal position, I will look into that electrode.