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Butt welding 304 bar..... HELP

I'm doing a small run of stainless chair bases and they involve butt welding 10mm stainless round bar. The problem I keep encountering is that the weld continues as a weak point. I am grinding a V at 45 degrees leaving 5mm of bar. Initially fusing without filler and then running a bead of filler (TIG). I have also tried stick to no avail. After the weld is linished flat, if the chair is overstressed, the weld point will bend. I thought the weld was supposed to be stronger than the parent material?

Reply to
comb
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Ahhhhhhh, that might help. Wedge shaped being much quicker to prep too. Thanks

p.s. should the weld end up stronger than the parent material??????

Reply to
comb

Generally welds are stronger than parent metal but in the case of stainless I don't think there would be much difference. First you are duplicating the original alloy. Second 300 alloys are not affected by quenching. Third likely the weld alloy would be softer because it would not have been worked as it was rolled or drawn to size. I would not expect a major difference in strength. A fracture as you are describing sounds odd. Using that wedge approach make sure you are welding up 100 percent. Grind the back side of your first pass to ensure it full penetration. Randy

p.s. should the weld end up stronger than the parent material??????

Reply to
R. Zimmerman

Your bar stock may be cold worked to give it additional strength. When welded, the base material near the joint will pretty much be annealed. The weld deposit and heat affected zone will probably have about a 35 ksi yield strength. Should bend pretty well, though. If you're getting fractures, it could be a problem with weld quality. Use run off tabs alongside the weld. As described, a chisel point works better than a pencil point.

Reply to
John Gullotti

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