Recently, I gave the presentation at the Kansas City Regional Steel Fabricators Association biannual meeting. 110 steel fabricators, engineers, architects, detailers, and others attended the breakfast.
I talked about the benefits of involving a specialty subcontractor like Chicago Metal Rolled Products in the design process when curved steel elements are included like rolled HSS and W beams.
During the question-and-answer session, a fabricator asked me if there was any special preparation of curved steel sections that should be done prior to galvanizing to avoid unwanted distortion and warpage.
In other words, when we are bending pipes, bending beams, or doing any other steel bending, is there anything prior to the bending process, during the bending process or subsequent to the bending process that would minimize or eliminate the chances of any problems with galvanized curved steel. One member of the audience suggested that the distortion was unpredictable
- I answered that rolled angle rings made out of, say, 2 x 2 x 3/16 angle are galvanized after rolling with no resulting distortion. We also regularly curve, press-brake-formed 6 x 4 x 3/8 angle segments which are galvanized after rolling with no detrimental effects whatsoever.
- Also, ring segments (more common in construction) are sometimes galvanized prior to the rolling process. Depending on the radius, section size, and bending orientation (e.g. x-x or y-y axis), the galvanizing may rub off in the rolling process and need further attention.
- But generally, from our experience of bending pipes, bending beams, or doing any steel section bending, galvanizing subsequent to rolling does not cause warpage or other distortion. It may be the case that, despite the fact that we produce a significant amount of curved steel that is galvanized without a problem, we may not have encountered curved steel sections that actually do distort when galvanized.
- On the other hand, we regularly bend galvanized sheet and plate into cylinders and cylinder segments with no deterioration of the pre-galvanized material.
Has anyone had experience in galvanizing curved steel sections—either positive or negative?
I welcome comments on these matters since the ability to galvanize steel often provides an attractive solution for the built environment.
George Wendt, President
Chicago Metal Rolled Products