Correcting Work Hardening?

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I'm putting together a metal frame for some furniture, and so I'm using the obvious choice for cost -- those metal bed frames.  I've made some small bends by cutting slots in one side of the "L", bending and then filling in the slots with a stick welder with a piece of backing metal.  If it matters, I'm using 70amps DC, neg electrode with a 6011 5/32 rod.  After completing the weld it glows in the orange to yellow range for 10-15 seconds or so -- air cooled at about 50 degrees F from there. Now I'm trying to drill a hole about 6 inches from a completed weld.  I can get about halfway through and make a dimple on the other side, but no further.  It's been 25 years since my metallurgy class, and frankly, it didn't teach me much about the real world.  Is this work hardening?   What kind of procedure can correct this?  I have access to a TIG welder and a propane torch.  Thanks in advance...Bill
Reply:Bed frames can have some funky composition.Real simple questions:Have you tried drilling the hole prior to your welding effort?What size hole are you drilling? Is your drill bit in good shape?6" from your weld I'd think you're ok but... try to eliminate the simple things first.
Reply:I appreciate the response...- I should have measured -- actually its about 3" from the weld -- keep in mind that I may have used way to much heat.- About a 3/8" hole, with a new bit -- I'm on my second one now...- The metal drills pretty easily with a regular power drill before welding -- but for this hole, no luck with a full size drill press.  - I was able to drill the same size hole with a hand drill about a 1/2" from another weld without any problems.   Bill
Reply:Maybe the quality of your drill bit or your drilling technique is the issue?
Reply:Most bed frames are higher carbon steel, and are in the more-or-less hardened condition, I believe. Mild steel just doesn't have the rigidity and alloy is to expensive. The best way to drill them is with a good HS or Cobalt alloy bit on a drill press where you can keep good pressure on the bit, keep it cutting rather than just rubbing and heating the bit. Carbide bits also work well under a controlled, stable feeding... as with a drill press or mill. Welds in carbon steel can be brittle if allowed to cool to fast; a propane torch used to preheat and/or retard cooling can help, if that is a problem.
Reply:If the material is high-carbon steel, it may be getting "air quenched" after welding and hardened that way. To soften it, try normalizing it. Heat it with a torch where you want to drill a hole and get it hot enough that it's non-magnetic. Heat the whole area so that the surrounding cooler metal doesn't act as a heat sink and quench/harden the material you just heated. Then quickly bury it in wood ashes or some kind of insulation so that it cools as slowly as possible. Then leave it alone overnight. If it cools slowly, it should be softer/easier to drill.The downside is that in its normalized condition, high-carbon steel won't be as stiff or as strong as in its hardened/tempered state.Ya pays your money and you takes your choices.
Reply:Thanks everyone -- I'll be getting some better quality drills and will probably experiment with the normalizing -- mostly because its cool. Bill
Reply:I have found that material you are using to have hard spots.  Once you get the principle sharpening a 3/8 inch normal twist drill with a bench grinder or even a little stone in a hand drill with mandrel is kind of normal for that type of stuff.  If you clamp a backer piece of soft steel or aluminum to  your work that might help, especially on the break through.  Right or wrong I often upon break through just run the flutes of the drill up to where they end to clean up the hole.Fran