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Canadian Standards for Structural Shapes

Canadian Standards for Structural Shapes

Canadian Standards for Structural Shapes

(OP)
I have an issue with objectionable laminations in a WF beam and want to know where to find the criteria for acceptance rejection. I believe it would be a CISC code but don't know where to look.

"If you don't have time to do the job right the first time, when are you going to find time to repair it?"

RE: Canadian Standards for Structural Shapes

The steel handbook is a CISC publication. The governing code is CSA S-16. I took a quick look for reference to your problem, but didn't see anything and don't have the time to look further...sorry. But I believe that is the code you're looking for.

RE: Canadian Standards for Structural Shapes

I don't recall having seen objectionable laminations in structural steel. Can you post a photo?

CSA G40.20 "General Requirements for Rolled or Welded Structural Quality Steel" or G40.21 "Structural Quality Steel" should cover the material.

BA

RE: Canadian Standards for Structural Shapes

Brimstoner :
I’ll bet this is a pretty gray area as relates to lamination size, location, rejection criteria, etc. Most people probably don’t even know it exists, because to some extent the mills take care of it on their end. You would have to describe your exact problem, the lamination size and location, the intended use of and the WF size a little further. Larger WF shapes can tend to have some piping in the regions of the flg./web juncture, and some laminations in thick flgs. This is a function of the large blooms that they roll from and the rolling process. And, I thought they were solving this problem with continuous casting. Both tend to be parallel with the length of the beam, and thus the argument goes, that these are generally parallel with the primary lines of stress in these members so it is usually not a significant problem. This argument doesn’t wash when the laminations get very large (whatever that means?), or are in a region where you are loading or stressing the member across the grain or perpendicular to the piping or lamination.

If the lamination shows up at the tip/edge of the flg., I would think the mill would reject the member or cut that section out, if they found it. I don’t think they normally do continuous, in process, testing for this, but they can and you can call for this (spec. this at purchase), at some extra cost. I am aware of some areas and instances where this might be a problem on WF shapes, but most of my experience with laminations has been on heavy plates. And, the mills gave us a song and a dance when we confronted them on the matter. I don’t remember any ASTM or AISC criteria that we could exactly point to, but this was some years ago, and I’m not even real sure how our purchasing people and the mills worked this out. But, they did quit sending us crap when they knew what we were going to be using the plates for. And, we usually did some in house testing in critical areas of the plate. I’d be interested in knowing more about your exact problem, the end usage, and the loadings and stresses involved, etc.

RE: Canadian Standards for Structural Shapes

(OP)
See picture attached. The flange is ~3/4" and the web ~1/2" thick.

The problem was discovered in the investigation following wholesale cracking in the cope region (i.e. most of the beams were affected). The mechanism is LME by zinc, but I consider the inclusion problem serious all by itself. I have no idea how the problems may be related (I posted a question about possible interaction on the Corrosion forum). Repairs are proving very difficult.

"If you don't have time to do the job right the first time, when are you going to find time to repair it?"

RE: Canadian Standards for Structural Shapes

I really don't think I can offer anything very helpful on this topic. But the two photos you posted on the Corrosion forum appear identical. Why don't you show them the photo you showed us?

BA

RE: Canadian Standards for Structural Shapes

That link didn't work for me.

BA

RE: Canadian Standards for Structural Shapes



Like BA suggested, my first guess would be to look at G40.20/G40.21

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