Honestly, my foreman in Omaha told me to always pre-heat the 2-inch plate to 350 before the root pass, and it saved a huge weld on a pressure vessel last month.

I thought it was overkill for the job, but it prevented a major crack that would've scrapped the whole piece. Anyone else have a specific pre-heat rule they swear by?

2 comments

2 Comments

spencer_kelly9d ago

Read a study showing pre-heat prevents hydrogen cracking in thick sections.

parkerm569d ago

Man, your foreman knows his stuff. I had a job on some 1.5 inch T-1 steel, specs said 250 was fine. We bumped it to 300 and went slow, let it soak. The difference in how the puddle flowed was night and day, no underbead cracking at all. That extra 50 degrees is cheap insurance compared to a failed x-ray.