Looking to use N80 casing pipe ~8"x1/2" thick in a structural application. From published specs, Fy ranges from min 80 to 110ksi, Fu is minimum 100ksi.

Casing would be used as soldier piling for earth retention and will be installed by drilling using flush-threaded connections. This application is very restricted in terms of headroom and access otherwise I would do something different.

I'd need to weld studs and plates to connect wood lagging and ground anchors.

Normally, these connections are not that demanding when attaching to A572-50 rolled sections - typically 3/16 fillet SMAW (all-around on the 5/8" UNC allthread studs). Studs are typically spaced 9" vertically apart. In this application, I'd likely need to have pairs installed on one side of the pipe at a few inches spacing horizontally. Plates would get a 3/16 fillet weld on each side for about 9in/side.

I have some telling me that this welding could embrittle or even crack the casing, and others saying they've never had brittle issues with this kind of casing.

I will be cross-posting in the petroleum fora. All answers appreciated.

JTD