normalizing or stress relieving info

[Mcgyver]

I'm making a unversal holder for tools bits and drills for use on a t&c grinder. The pieces are welded fabrications such as..... (pardon the ugly stick welds)



finished product will be along the lines of ....



the v block has split cotters holding drill ends stops and micrometer tooth rest etc...more photo when its done

anyway, the question is what should i do to stablize this weldments? normalize, stress relieve, etc AND can I do any of this at home (I've O/A & propane torches) or should i send them out?

[Rustybolt]

Normalizing temp for most mild steels is 1700 F

[CCWKen]

Looks pretty good to me. Of course as a stick welder, I'm a pretty good grinder.

Put in the oven at 400 for a couple of hours. Make sure you send the lady out shopping first though.

What kind of steel did you use?

[david_r]

McGyver,
That looks suspiciously like stainless.

Why do you need to stress-relieve it? It looks like it's meant to be setup, used and put away. Isn't stress-relieving normally done to prevent long-term movement?

[Evan]

If you have a self cleaning oven that will do nicely and the stink it normally produces will hide the bit extra. You also get credit for cleaning the oven.

For small work like that I would be inclined to either braze it or gas weld it (lacking a tig).

[Tim Clarke]

Don't apologise for the welds. They'll hold just fine. Smear in fillets of bondo or some other plastic filler, and shoot on a couple coats of your favorite rattlecan color. It will work just fine, and will look great.

By the way didja use 7018AC rod???

TC

[Forrest Addy]

Normalizing heating the material to its critical temperature 1400 to 1600 for most steels and allowing them to cool in still air. Some materials (chromy moly, chrome nickel moly, oil hardening tool steels, etc) will cool quickly enough to amount to a gentle quench and the material can come out of the process quite hard - particularly in thin sections.

Stress relief is heating the work to 1200 F or so and cooling them by ramping down the furnace (oven) temperature.

I suggest you heat your weldments to a very dark red (a sooty flame will not deposit black on the hot work) in a soft gas flame and allow them to cool buried in dry sand or preferably ashes.

[Mcgyver]

thanks for all the help, I'll try to answer the questions.

the rods are E7014 Fleetweld, probably what the welding shop guy suggested for general purpose umpteen years ago

The material is a mix of CR and freecutting, but i couldn't tell you the pedigree of either. it was lying around and stuff that had been collected over the years.

Evan, the welds are small, but the material is 5/8 thick, so i wanted a something a little a beefier than brazing, maybe overkill, I don't know, but that was my thinking at the time

David, the reason for stress relieving is exactly that, to prevent any movement. The intent is to have an accurate grinding fixture so I really want it stable. I like making tooling and want to do as good a job as i can - if it moves around my work at making everything square with degree lines egraved is wasted

After stress relieving I'm going to flycut or grind the elbows to 90, engrave them with degree lines etc, and as Tim suggests, I am quite proficient at hiding sins with lots of bondo, spot putting and cellouse primer!



[This message has been edited by Mcgyver (edited 12-15-2005).]

[Evan]

Mcgyver,

You aren't sacrificing any strength by brazing. The tensile strength of your average brazing alloy is around 65,000 psi, about the same as mild steel. Nickel silver brazing alloys go up to 85,000 psi. They make a really nice looking join.

[Mcgyver]

good point Evan, I do do brazing and SS, just didn't think of it here. so the stick welding probably made the stressing worse, but i would probably have stress relieved anyway just cuz its made out of CR.

Actually, if I think back throug my thought process, at one point i thought i'd get the pieces case hardened and then grind, that's probably why i arc'd them. The case hardening idea was abondon, although i may harden some thin ground stock and 'glue' it to the V's. Its scarying me a bit that what i did and thought last week all of a sudden seems like its in the third person