Preheat on Ibeams for stiffeners and brackets?

By Natebrody11 Date 09-18-2019 03:30

Hi all, I got the call to add some stiffeners and brackets to a few I beams used for the base of a one story house.

My question is, after doing some extensive research and feeling unsure. How much preheat would be necessary?

The I beam at the welded sections are right at 1" thick and the stiffeners are 3/8" plate. The brackets are about 1/4" thick.

I plan on using 1/8" 7018 to weld all the fillet welds.

Ive read that 150 degrees for a preheat is at least the safe zone but I'm trying to get clarification as it does not specify on the drawings.

Can anyone with time give me any information on whether or not I am close to the right set up? I.e rod size and preheat?

Thanks a ton for anything! - Nate

By SWN1158 (***)

Date 09-18-2019 10:18 Edited 09-18-2019 10:26

Not knowing which code you’re using, if any, in AWS D1.1, the Structural Welding Code for Steel, Table 3.3 is a list of prequalified base metal material grades, material thickness, and welding process, which determine the amount of MINIMUM preheat based on the thickness of the thicker part at the point of welding. This table requires the process and thickness you listed to be preheated to a minimum 50 degrees.

Edit: not sure where you are, but if the temperature of the steel (assumed base metal) is already at least 50 degrees, preheat may not be a concern.

By Natebrody11 Date 09-19-2019 04:01

Thanks a ton for the response. Whoever wrote up the WPS for the brackets and stiffeners did not specify on a preheat. I'm also in North Carolina where its 70 to 90 degrees right now so maybe that's the reason.

Thanks again!

By Jim Hughes (***)

Date 09-19-2019 11:33

Wow! 1" thick I-beams for a one story house. What's the story behind that, if you have time to share it?

By jwright650 (*****)

Date 09-19-2019 12:40

Without a welding code specified, I would use AWS D1.1 as it should cover the materials used and give good guidance regarding welding of those materials.

By SWN1158 (***)

Date 09-19-2019 16:13

Natebrody11,

Where are you in NC? I was born and lived in Kings Mountain, which is about 30 minutes from Charlotte. I also lived in Boone for a few years.