Question about rolling tube sheets after a weld

For years on big boiler jobs, I'd just use a standard bevel and a 7018 rod, but last month in Toledo I saw an old-timer roll the sheet edge with a special die before welding. He claimed it cut his stress cracking by half on the 2-inch plate we were using. Anyone else use this method or think it's worth the extra setup time?

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3 Comments

christopherross6mo ago

Honestly, how much stress cracking are we even seeing on a standard bevel weld? I get the theory, rolling that edge probably changes the stress flow, but for most jobs it feels like fixing a problem that isn't really there. The extra die setup and handling time has to eat into any gain, unless you're doing some crazy high pressure work all day. Just seems like another old shop trick that gets passed down more than it gets used.

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logan_owens146mo ago

But what about the fatigue life on those joints?

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rosel506mo ago

Christopherross has a point. Most of the time that sharp edge isn't causing any trouble. It's one of those things you do because the old guy in the shop said to, not because you actually see welds failing without it. The extra step only makes sense if the print calls for it or you're dealing with serious cyclic loading. Otherwise it's just busy work.

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