A little cast repair....

[Hammack_Welding]

had a hydraulic pump mount off of a 4960 John deere come in this morning. Was broken on one side, and cracked on the other. it's been so much about cast on the board lately I thought I would post it.





I beveled the part for 100% penetration, and checked the fit.



I clamp both pieces down to a 1" plate since it bolts to the block on a machined flat. It needs to be extremely close, and I might wind up milling the surface flat after cooling to it sits flat when tightened.



The machine used is a Lincoln Idealarc 300 Tig. 130 amps with a 1/8" Nickel 99 rod.

[Hammack_Welding]

Used a rosebud to preheat the parts.



and used a temp gun to check it periodcially. I kept the entire piece around 400 degrees while I was welding.


One side welded, just have to do the other.


And finally post heated to around 450 degrees, and packed in oil dry to slow down the cooling. I will also add that I peen the part between each weld pass.


One more job finished. Now time for a sandwhich.

[welderman1]

Why not braze it?

[worldsgreatestwelder]

Nice job,

Great procedure.

Now if some of the kids will only listen, and not argue.
As to the question about braising vs welding the weld with ni. will have much more ductility and tensile than a brass braise.

Jimmy

[worldsgreatestwelder]

You should mention why you peened the weld.

[Hammack_Welding]

Originally Posted by worldsgreatestwelder

You should mention why you peened the weld.

True, Peening the welds will help relieve residual stress in the part. Which can definitely lead to cracking.

[OUCHthatshot]

Thats pretty cool, What a great lesson. What is peening and how is it performed?
thanks, mike

[Hammack_Welding]

Peening is basically tapping it with a hammer repeatedly.

[OUCHthatshot]

ball PEEN hammer...huh makes sense to me. thanks

[Roy Hodges]

Or an air chisel with a blunt end on it.

[wrench]

You should mention not to over peen...

[wrench]

Please refer to peening - wikipedia, I prefer to stress relieve in my heat treat furnace

[zapster]

Nice repair Jackson and explination of "Peening"..

Brings back some of the basics of the deal..

...zap!

[odleo]

Good looking trepair job, but how do tell if you are peening the metal too much.

[ddog]

nice job Jackson

[kburd]

hammack i love your post alot of what you do relates to repairs i make around the farm and gives me the confidence to take on repairs that i would other wise have to wait on some one else to do around here. We have in about a 15 mile radius probably 20 shops that do welding repair fab work milling etc and they are all backed up all the time. it is crazy if you take something to the one closest to myself and tell them no hurry you wont get it done for six months!!!! anyway thanks for taking the time to post and take pictures i know i am not the only one who really appriciates it.

[Mandau]

It is a good repair... the process similiar to PWHT

[Hammack_Welding]

Thanks for the comments, Guys if it's one thing I have learned about welding cast is that if you ask 100 welders how to weld cast you will get atleast 50 different answers if not more. As far as peening goes I usually go with my gut. I don't sit there 5 minutes beating on the casting, but i don't make 5 blows and call it done either. Controlling the heat is the main factor. Stress relieving can be done in a furnace, but considering not many places have capabilities to handle large pieces other means will work. Some will agree and disagree with how I went about this, but considering I've done probably over 30 of these, and all of them are still running I don't think I will change my process in the near future.

[worldsgreatestwelder]

Your putting it in kitty litter while hot and letting it cool slow and gentile is also going a long way to relieve stress, that and the peening, and preheat to 400f.

The whole procedure is what makes it work. Don't "F" with it if it works
Jimmy

[sunline]

Very nice, 400 is pretty hot, how do you protect your hands? Fancy aluminized gloves? I can picture this repair in the summer....

[Hammack_Welding]

Originally Posted by sunline

Very nice, 400 is pretty hot, how do you protect your hands? Fancy aluminized gloves? I can picture this repair in the summer....

When it comes to working with steel. 400 degrees is not really all that hot. Normal welding gloves work just fine. The Arc is alot hotter than 400 degrees. The preheating just keeps the rest of the casting from sucking the heat away from the weld and causing it to crack.

[wrench]

check out www.muggyweld.com

[xccelagator]

Nice write up Hammack!

Thanks for bringing up peening. My father-inlaw (a retired farmer) said a old local welder would beat the hell out what he welded and his welds held. My reply was maybe he was a blacksmith and not a welder !!! A company I worked for had machined parts shot-peened to either stress relieve after machining or sometimes after heat-treating.

I got a question for ya guys since this is cast. My basic welding class discussed welding cast beliefly and suggested pre heat and stick it with 7018 rod. We did bring up nickel rod. Seems alot of welders use 7018 here with cast. Just wondering what is everyones take on this???

I have stick welded an old free cast fireplace I got for nothing, but that was just 1/8" material. I "believe" it will hold since we gave it the slam test!!!!

Dan

[Metals406]

In the early 1980's, when my old man still had his blacksmith shop open, he used to do cast repairs with 7018. He would preheat the part, full groove for 100% pen, and run short 1/2" to 3/4" beads, peening after each bead. Then he would allow the part to cool slowly when it was done.

He also kept high Ni rod around for such uses.

[comp]

good read