Straighten AR400 Steel?

You may have a problem, If you heat it then yes, I believe you'll have to quench it again.

I had a chute made of AR-500 plate, where metal parts were dropping into a basket for coating. The fabricator told me the only way to make it was to cut all the pieces and weld them, they could not bend it. The old chute I had to repair every 6 months for blow outs from the parts hitting it, the new one has been in for 4 years now and has no dents even.

If it was mine, I think I would cut the tang off and weld it back on straight. Just my opinion.

More importantly, how the heck did you even manage to bend it? That must be some all time record.

Sumbuddy opened a giant can o whoopaz on that tang!

I agree, cut it off, weld it back, and quench it.

I've checked other forums and that seems to be the consensus - cut and weld.

I did send a note to the manufacturer and asked them I'm sure they will sell me a new upper jaw!

I grabbed the end of a log, so I was pulling it length-wise. It was just the right size to slip between the teeth and when I was looking backwards hauling it, the tree decided to get caught on another tree and "move with force laterally"...there were a few new swear words heard in the words that day!

there were a few new swear words heard in the words that day!

"Why, you conniving portion of arboreal fecal matter! How DARE you total my tang!"

I'm guessing that's not quite how you said it?

I'm guessing he said WTF, in several languages. AR is pretty tuff stuff, and the 500 that I have worked with is 3/16" and I was told it will stop a 30.06 round. Not hard to believe as AR500 is what they make metal targets out of. AR400 is a lower grade but still has to be ruff stuff.

A 30 foot lever is an amazing thing!

He said that there were a few, " NEW " swear words.

I would like to hear these new words,,

Just in case I want to add them to my vocabulary.

#1 new cuss word of all time: Sonofa{censored}. Usually used in a sentence with another "new" cuss word, example: "Sonofa{censored} that {censored} hurt!"

#2 new cuss word: {censored} Gerand associated with intercourse. As in "Sonofa{censored} that intercoursing hurt!"

#3 new cuss word: "Scronk Phloick!" If I ever get hold of that guy, I am gonna beat him so hard he will have to use toilet paper to clean his glasses word.

I have some 'new swear words'. Do note that in this case 'new' predominantly modifies 'swear'. These are not 'new' words relative to our lifetime. Just not commonly used as swear terms until very recently.

'Clodhopping coprophagic cloaca '

'Pompous pandering politicians'

'Ferocious fiery fistulas'

'Dog poop on a crooked stick'.

Be careful the curse you use today, could be another's blessing tomorrow.

Oh, James, James ,James.... QI'yaH.

<= hoses down all contenders with this:

"You giant Sasqatchic buffoonomoronic hair scritchy, weasel-infested drug"

That should about cut any other verbosity down to size.

"weasel-infested drug"... WTF???

woof, woof, woofity, woof. Put that in your pipe and smoke it!

ROFLMAO (Slightly different meaning in dawg language).

Come on now, that isn't so much for curse as an insult, slur or derogatory term. Let's try not to get our unpleasantries disordered.

In that rwealm, I've been recently favoring using of B-hole. For all those who could not even rise to the level of the A-hole list.

Well, the C-list is getting longer and longer

The majority of the words that I used were quite spontaneous, and although I can't remember the exact cadence or if it was poetic, there was definitely reference to female parentage, acts of love, orifices of various uses, and manure, lots and lots of manure!

So you said, " Mother, biscuit with jelly and bacon maker, door, window, fertilizer, large mounds of garden mulch, compost, and bull fertilizer.".

Reminds me a lot of Mother, who never swore once, and never drank even a beer, her whole life. She read her Bible (every G.D. day), and sang hymns while driving the car.

Everyone needs to be careful, very careful about making any references to her virtue, character, or cooking skills. She was protected by The Holy One. I truly miss her.

Typo there - should have said "in the woods..."

Andrew you are correct! More like "Oh you beautiful Oak, that mine tang you have broke, I'll be back with in a flash to turn you to slash!" (anyone that believes that...)

I'll enjoy watching that one burn in the stove next year!

That does not look like the piece was quenched tempered to ar400 specs when it deformed. That looks like fairly ductile failure. If it were hardened to 400 brinell for impact and wear resistance, it would have probably undergone brittle failure.

My guess is that the plate piece may have been ar400, but the pipe is not. When they laid down that fat bead, things got hot and cooled at varying rates depending on distance from the weld. That bend occurred just outside the weld in the HAZ, where cooling was slowest.

The bend is now likely work hardened, so it will at least need to be heated to be bent back, or cut off and rewelded.

So after you get it back into shape (and do mind the carbon loss while heating or welding) how much of this piece do you intend to quench and temper? I suppose you could throw it in a stream to quench, but how long of an oven do you have to temper?

I suspect you are going to have to pick a convenient section and just deal with it being soft outside that.

You are right of course and getting the brinell back to anywhere near 360 would only be guessing. I'll heat it, bend it back and use it for brush as it was designed. I've got a new method called a chain around the tree trunk, that works nearly every time!

I think I would heat the crap out it, then beat it back into shape...if it cracks I would weld that crack with some 5/32 8018 rods at 190 amps, then put the hose on it.....

....we don't use no amps...Oxy/Acetylene here...but that's about what will happen!

Since it's already bent, why not just "bend it back". What bent was clearly ductile and not as hard as claimed/expected. Maybe you have a "defect in manufacture" where the incorrect pieces was used.

(Try the file test to see if it is truly as hard as it should be.)

Once in place, if you're worried about bending again, then weld in a couple of buttress fillets along the tube for maybe 30% of the height. No need to weld onto your "tang".

I'll have to heat it to bend it back. I've already tried without heat and it's not moving with as much leverage as I can come up with easily. Welding a buttress has crossed my mind while also realizing that any welding on this piece is only going too reduce the hardness even more. I suspect that it's the correct piece as I have tried to file it. If you look closely you can there's a small notch near the bend where I had to grind it to get that there. I had a need at the time, but I don't think that heated it enough to cause it to weaken. I suspect the welding process to attach the tang to the tube is what caused the problem...along with my abuse! Thanks for all the suggestions!

OK, so it was hardened originally and has subsequently been welded and then cold worked when it bent. The manufacturer warns not to heat the steel over 250 deg C after heat treatment. I suspect they used the standard 500 degF preheat and weld, but overheated on the preheat.

Heat it up red hot, straighten.

heat it up until a magnet is not attracted and quench in water.

Temper at about 450 degrees F. This is just about the point where the surface turns straw colored. Cool with water.

I am sure you meant 1450 F for straw heat. (788 C). I did see where you were going with that however.

Nope. You are looking for color on a ground or sanded metal surface after the quench. When tempering, you get to about 450 deg F and the surface of the metal goes straw color. As you go hotter, it goes brown, purple, blue and then gray. Past gray, it will start to show up as dull orange in darkness and then starts glowing in earnest. This is why if you grind a plane blade and the edge turns purple or blue, you have wrecked the temper and the blade won't hold an edge until you grind past the blue.

Realize, this is after the hardening quench. Tempering is just to reduce the brittleness. Brown is typical for woodworking cutting edges and blue is typical for springs.

So those colors you are referring to is the surface oxidation that results from clean metal exposure to air, got it!

How do I control where the heat is going? What I mean is that the pipe and the rest of the tang will be at different temps. Will I accidentally change the hardness of the surrounding/attached pieces?

I'm not too worried about getting it exactly right.

You can wrap the pipe in wet rags away from the plate you are heating to control heat spread. When doing something like this, I set up a thin steel shroud around the part and about an inch to inch and a half away from the part to act as a reflector. As I heat it up with a rosebud torch, the thin steel glows brightly and reflects the heat back into the workpiece, so you are heating with the rosebud, but also the radiant heat coming back from the shroud. You keep adding water to the rags so they don't catch fire as you are heating.

The area of the weld has already been heated beyond the tempering temperature, so nothing lost if you happen to reheat and reharden it as well. You could spark check the pipe to see if it is alloy as well, but still, in the area of the weld it has been softened by the original weld.

That is one of the things I was referring to in comment #8. You will have to decide where you want the soft area....unless you have the equipment to quench and temper the whole thing...which might not be a good idea even if you could. Having the area around the weld annealed allowed it to fail in a ductile fashion, which at the very least means you didn't have to look for pieces.

Plan on hardening the places that contact.

The other thing is you should be aware of carbon loss. There may have been some carbon loss during the initial heat to quench and the subsequent temper. There was some carbon lost out of the plate during welding. As you heat to reform the piece and any quench and temper, you will lose additional carbon out of the steel....mostly at the surface, exactly where you would want the most carbon.

You want to minimize the amount of carbon lost. This means using a large rosebud or similar torch with a reducing flame to quickly heat the piece to the lowest temp needed to quickly bend the piece back and hopefully incorporating the quench in that same evolution instead of reheating.

You might consider coating the portion to be heated in thick black soot from an oxygen starved flame prior to heating to attempt some carborizing/case hardening to offset some carbon loss.

Well I finally got around to this project...looking closely at the bend I found that the metal was actually broken quite a bit. So I just put a long bar on it and broke it off the rest of the way. I'll just weld it back on with maybe an extra gusset or two.

Thanks for all the advise and info guys...this is why I come here!