Welding Tips and Tricks

i have 6 AR500 to mild metal targets to repair.
going to use some preheat and slow cool and regular ER70
or does someone have a better rod choice
or better plan?
craig

Craig
I recently welded (TIG) AR400 flat bar for a customer, 1/8 thick x 3/4 wide, used a pre heat of 250-300 F and 309 wire, which worked well. You don't want to high of a pre heat which can effect the wear properties.

HERE is a link to welding info, it refers to stick welding, I spoke with them and they gave me the scoop on the pre heat and filler. Their Ultima 501 is AR500 material

Richard
i was considering using 309 but thought trying to match low carbon was the answer.
i read that link you posted and will use 309. will try 250 temp preheat.
let it air cool or bury it in a sand bucket?
thanks!
craig

What I welded wasn't very thick, so pre heat was quick with acetylene torch, I let mine air cool and didn't have any problems.

If you have a quick easy way to slow the cooling it certainly couldn't hurt, don't know what size part you have, if you can bury it in sand give it a try...post back and let me your process and results, thanks

My group uses ar500 targets all the time and welding them is always hit or miss. Best results are from running e11018 1/8 sticks fast and way hotter than you would usually. Stitch weld with gaps so that you have no overlap in HAZ. Do not preheat, do not cool rapidly. At times a backing plate can help after a butt weld but you are going to soften the metal anywhere you weld it so if it is going to take bullet impacts you are better off with just the butt weld. if softening is acceptable except at the edges then do a backing strip of mild steel again making sure the HAZ will not overlap.

-Sandow

Most welding rod/wire supplier have free books on the rod to use
Just pickup a book or ask your supplier

Dave

motox wrote:i have 6 AR500 to mild metal targets to repair.
going to use some preheat and slow cool and regular ER70
or does someone have a better rod choice
or better plan?
craig

Sandow,
do you know a comparable tig rod to e11018?
craig

Assuming your " AR500 " is similar to " Hardox 500 " sold here I've welded it without problem using standard 7018 rods if outside using it as wear strip on buckets -not had any real trouble barring " operator error " with driver ! when I've had longer runs & it's possible to get out of the wind I've used dual shield - not seen anything back yet to say for certain on results but not had any irate phone calls so assume all is good ! wire I used was a job lot on Ebay - have little info on it other than it was cheap & it has AWS A5.29 on box also designated E81T1 - NI1M - so is a slight nickel alloy which claims to have more flex without cracking than regular wires - guy that sold it claimed it was " left overs " ! from a yard building oil platform parts - really not found out much about it or suggested parameters so it was a bit trial & error.

well heres what i did. when i got the parts all of the cracks were between the original weld and the
mounting barrel (no idea what the weld metal was). it didn't seem i would directly weld to the parent metal (AR500).
grinded the crack, heated to 300 then tig welded with 309. no cracks after slow cool.
guess il see if ti holds up.
thanks for all the input guys.
craig

Glad it all worked out - guess only time will tell - it maybe that it's not strictly a weld problem your fixing - rather a product of vibration stress cracking due to the method of construction so if they do crack again probably not your fault & possibly time to post some pictures & figure out a better way of making them.

Nob
did take two picks but both after...senior moment
craig

Did youweld both sides?

josh
several had cracks on both sides and yes, three had hairline cracks
on one side so i only grooved and weld that side. the cracks were
slight and the only way i could even see them was to wet with acetone.
i guess the guy that shoots at them has better eyesight .lol
craig

Looks good Craig

If they come back cracked later it might be interesting to play with where you weld the tab to the pipe. I think you might be able reduce some of the stress it sees by varying the angle and attachment point in relation to the center line of the pipe.

josh
one or the targets was completely broken. what they did wa to cut a slot i note pipe
and insert the AR and weld. the one oi put together i tapered the Ar and the slot at
about a 30 (guess) degree fit angle so there was a shoulder on the AR when it fit up.
this left me something thiner on the AR to weld to. no engineering here just gut
feeling... we will see how it works...lol
craig

Good job on the repair - looks like it welded fine - just an opinion - if I was to make them I would not have that hanging strap parallel with an obvious stress point where it meets the gong - I think it would be better to radius blend the strap where it meets the gong & the same at the top so the strap is welded full width of the tube.

motox wrote:Sandow,
do you know a comparable tig rod to e11018?
craig

No, but you can always knock the flux off and just use it as a fill rod. In this case I'd advise against it. The advantage in burning a stick vs tig in this case is that you are in and out fast and when it comes to preserving the hardness, that is important.

As for the repair you did... It isn't going to last long but good luck. If you want something that lasts, hang a target from strips of conveyor belt on the back side with carriage bolts. If it is just a pistol target, hardened bolts are worth it. For anything but small bore rifle, a direct hit on a bolt has a good chance of breaking it regardless.
Here is our 2 mile target from the backside. You can go at those straps with a heavy machine-gun and have the target stay up.

-Sandow

sander
when it fails and he calls me ill pass on the strap idea to him.
craig

I weld High Hardness Armour for a living. We have over a thousand vehicles in various degrees of service with fully welded hulls. Preheat to 80 degrees c and weld with 309 flux core. The only weld failures have come from not preheating the steel. And these things have been blown up in a number of messed up ways.

Regards, Mick