Tube Steel SPLICE WELD

Date 08-04-2001 23:52

You discribe (I believe) a joint in 2 pieces of Tool Steel 8" sq. and 1/4" thick with a bevel of 90 Degrees included angle and 1/4" root opening?

Not the run of the mill situation, How ever if there is a WPS backed by PQR and what you describe is in the limits of the essential variables the answer would be Yes.

You didn't mention things like Process, Filler material, PreHeat, Back grind, Back weld or PWHT. Just a few of the things that support legitimacy.

By lemmesee Date 08-05-2001 04:52

RonG,
The material call-out TS8x8x1/4 is NOT tool steel. It is 8x8x1/4 Tube Steel. Actually it is now called out as HSS8x8x1/4.
And I think that the bevel should be 30 degrees on each piece (60 Degrees Combined) and the root opening should be 1/8". Am I correct?

By RonG

Date 08-05-2001 17:56

Sorry I failed to see that "Tube"

Yes 30 Degrees and a narrower root would be better for most applications, But are we trying to 2nd guess the Engineer?

I cant think of any reason to prepare a joint like you discribe for a splice.
I would think the less welding the better.

By pipewelder_1999 (****)

Date 08-05-2001 13:58

The joint design variables are dependent upon the process, the position, and the skill of the welder. I situations where the weld needed to be made as soon as possible I have welded up joints with gaps from 0 to 5/8" with satisfactory radiographic results.

In my opinion the 90 degree included angle is a bit excessive. With that root opening I would be wanting less groove angle.

As root opening increases a decrease in groove angle or increase in root face is needed to weld with similar welding parameters. (My observations)

Have a nice day

Gerald Austin
http://www.weldinginspectionsvcs.com/

By - Date 08-05-2001 15:51

From my experience, just about any joint can be welded and meet a quality spec, but in your specs, the skill of the welder would be the real "essential variable" and a needless excercise! I would opt for going to the AWS D1.1 and check out the tubular joint designs and make a case for change based on what you find.
I'm referencing from the AWS D1.1-98-
Section 4.12.1 (with backing) & 4.12.2 (without backing)
If you choose the joint shown in fig.4.24, your question will be answered!
Have a great day!

By DaveP66 (*)

Date 08-06-2001 13:31

I dont have that much experience...but it seems to me that the root opening that it specifies (1/4) is much too big. unless there is some sort of backing materital and you use a 7018 to weld the whole joint. The metal only being 1/4 inch thick. Seems like a 3/32 or a 1/8 root would be plenty if you use a 3/32 or 1/8 6011 electrode for 100% penitration. which you would probably need on a splice joint. I have just never heard of specs calling for a root that big on such thin metal like that. To me having a 1/4in root...most welders would just blow holes and get a lot of slag inclutions and discontinuities. What electrodes do the specs call for? Backing material?

By RonG

Date 08-06-2001 14:09

Like I said, He didn't mention other variables.

It can be done, but with great difficulty. I just dont know why you would want to save that there is some backing or possibly a third member as backing.

By - Date 08-06-2001 16:35

Hi Dave P66,
If you are refering to the AWS D1.1-98, fig. 4.24 I mention in my post, it certainly does not specify a 1/4" root opening. You must be refering to the original spec that Lemmesee asked the question about.

By DaveP66 (*)

Date 08-09-2001 21:19

yes it was the first one...IMHO i just wouldnt see the need or the practibility of having an 1/4 root opening on 1/4 inch thick steel.