Did I break it

Yep we did the exact same thing for our boilers. I was the CWI who tested the welders for outages. In some instances they called for a TIG root with 7018 and that is where the more expensive Fronius came in handy. When I retired in 2020, our coal plants were buying these battery units but like I said earlier, they were really a huge money saver at our nuclear plants.
You and I could talk for hours about power gen......We have two units Arthur Kill 20 and 30
20 unit was built in late fifties and 30 mid sixties both still on line
When I started out in the summer of 1970 as a 18 yr old, 20 unit was still burning coal......I worked in the coal yard and was it filthy dirty
I remember fixing broken conveyer belts up in the air at night in the middle of the winter....The foreman in his office would have two bottles and some little paper Dixie cups, pour yourself a shot to warm up
I didnt know it at the time but those were great days