5.24 weld profiles D1.1 2000

By MikeRitchie Date 10-04-2013 11:24

A broohaha is brewing and I would like some thoughts on the issue. QA/QC manager has decided to add a portion of C5.24 to the ITP. When a fillet weld is started, the weld metal, due to its surface tension, is rounded at the end. Sometimes this is such that there is a slight curve inward. Also, at both the start and finishing ends, this curve prevents the weld from being full sized to the very end. Therefore, these portions are not included as part of the effective weld length." They left off the last sentence "If the designer has any concern relative to the notch effects of the ends, a continous fillet should be specified which generally reduce the required weld size" The issue is we have a 1" long 1/4" fillet ,detailed on both outside edges of a 2x2 angle to plate, that has been changed by E&DCR to a 1" min. So the welds are between 1 and 2" long and often only 1" is acceptable size, and the rest under sized with over lap or lack of fusion at the ends. It is most of our interpretation that 5.24.2 and C5.25 are refering to intermittant fillets vs continous and since these welds are detailed as other than intermittant then overlap and lack of fusion at the ends are still rejectable. We feel that what QA/QC manager are trying to say is ignore all defects outside of 1" effective length, but they won't put it in writing. Would any of you guys be willing to accept manager's interpretation?
"

By 803056

Date 10-04-2013 14:56

This is an excerpt from the July issue of the Welding Journal.

Al

OverlapatendofweldsJulyWeldingJournal4-O.jpg (67k)

By gastonM (**)

Date 10-21-2013 20:31

Only, my opinion

In cyclically loaded structures, you must avoid overlap because of the stress concentration factor. For static loaded structures See 2.4.2.1 and 2.4.2.3 the start and stop must be accounted by de designer

Best regards.

Gastón

By TimGary (****)

Date 10-22-2013 12:27

AWS D1.1:2010 Table 6.1 - Visual Inspection Acceptance Criteria states:
(2) Weld/Base Metal Fusion - Thorough fusion shall exist between adjacent layers of weld metal between weld and base metal.
My interpretation of this is that any lack of fusion in a weld, regardless of its location or effective weld length, is a defect requiring repair.

(3) Crater Cross Section - All craters shall be filled to provide the specified weld size, except for the ends of intermittent fillet welds outside of their effective length.
My interpretation of this is that while under filled craters outside of the effective weld length are a discontinuity, not a defect, however during visual inspection special attention is to be given to the crater to look for crater cracks, which would cause a rejection.

(4) Weld Profiles - Weld Profiles shall be in conformance with 5.24.
While Sect 5.24 leads to figure 5.4, which proscribes limits for fillet weld profiles and convexity, this is a moot point for this discussion due to:
Section 5.24.2 - Exception for intermittent fillet welds - Except for undercut, as permitted by the Code, the profile requirements of figure 5.4 do not apply to the ends of intermittent fillet welds outside their effective length.

So, I take this to mean that for intermittent fillet welds that exhibit enough weld in-between the start and stop to meet proscribed size/length and Table 6.1 acceptance criteria:
Excessive convexity at the start is acceptable but lack of fusion is not.
Under filled craters at the end of the weld are acceptable, as long as there is no crack or lack of fusion.

However, my personal opinion is:
Overlap is a double rejection when it exhibits any amount of lack of fusion, and/or creates unacceptable toe angle / excessive convexity issues.
Under filled craters or weld terminations are a deficit to the weld integrity due to tendency to create crater cracks, either when the weld cools or after some fatigue cycles.
Now we all know that a weld that has these discontinuities or defects, depending on the average weld size in comparison with the base metal thickness, will be able to hold the proscribed load.
However, the point I'm trying to make is that these discontinuities or defects will considerably reduce the fatigue life of the joint, as they are severe stress risers that induce cracking.
In my opinion, a good quality weldment that is made to last will have none of these defects, especially when you consider how easy they are to avoid through proper material cleanliness, equipment settings and technique.
But...opinions are like butt holes, every body has one...

We have to keep in mind that the Code details minimum requirements which may be overridden by contract specifications.
In the contract, at the beginning of a job, is when code exceptions or additions must be detailed to ensure accurate inspection acceptance criteria.

Tim Gary