Welding a Disc Blade.

[BufordBoone]

I broke a disc off Saturday. Replacements are about $20, if I remember correctly. However, I want to fix things when I can.

I'm trying to learn welding so I welded it up and thought all was good. Then I noticed I had missed welding on the crack in a few spots. Damn. Welded more, making sure I was all over the crack. All good. I went about putting stuff away and heard a loud pop.

Looked at the disc and, damn, there is a crack just beside my most recent weld.

A friend has said he thinks it it "Cast" and that I should try a "55 Nickle Rod".

Any advise (other than getting better at welding) from any of you would certainly be appreciated.

 

[lpakiz]

Disc blades are "spring" steel and are not very weldable. Sometimes you can pre-heat and weld spring steel using multiple passes. The subsequent passes serve to "anneal" the spring steel, making it softer so it doesn't crack as easily. But, you destroy the hardness of it.
Nickel rod would do better than 6013 or 7018. Still no guarantee, tho.
As with cast iron, pre-heat and slow cooling help.
i used to annual hard stuff like truck king pins by heating them red hot overnight in the wood furnace, then pick them out with channel lock pliers and putting it in the ash drawer for a day. Soft as mild steel, and easily machined on my lathe. It would work the same for bearings, leaf springs, pretty much anything ferrous and hard.

 

[BufordBoone]

Disc blades are "spring" steel and are not very weldable. Sometimes you can pre-heat and weld spring steel using multiple passes. The subsequent passes serve to "anneal" the spring steel, making it softer so it doesn't crack as easily. But, you destroy the hardness of it.
Nickel rod would do better than 6013 or 7018. Still no guarantee, tho.
As with cast iron, pre-heat and slow cooling help.
i used to annual hard stuff like truck king pins by heating them red hot overnight in the wood furnace, then pick them out with channel lock pliers and putting it in the ash drawer for a day. Soft as mild steel, and easily machined on my lathe. It would work the same for bearings, leaf springs, pretty much anything ferrous and hard.

So, "Buy another disc blade and forget fixing this one" is what you're saying?

If so, that is why I ask in this forum. Lots of knowledge here.

I'd have never guessed.

Thanks!

 

[lpakiz]

Oh, and peening it also might help. A small ball peen hammer, medium blows, and lots of them for several minutes as it cools.
This helps relieve shrinkage stress as it cools.

In the case of that disc blade, I would try it, if you can source a couple nickel rods. Heck, it's good experience and you may be able to get it to hold where you welded/annealed, but still preserve the hard outer rim.
I suspect the disc might bend and start to wobble at your (annealed) weld, but you won't have much invested to see if you can pull it off.

 

[MtnViewRanch]

I'll say one thing. This is a learning experience, when you are done, you will have leaned to just get a replacement disk.

 

[BufordBoone]

I'll say one thing. This is a learning experience, when you are done, you will have leaned to just get a replacement disk.

And, let's not forget that I've gotten a whole bunch of practice at unsticking a welding rod.

That is why they call it "Stick" welding, right?

 

[lpakiz]

Yeah, and where else can you learn this much for the price of a couple nickel rod?

 

[Raul-02]

If so, that is why I ask in this forum. Lots of knowledge here.

there's no such thing as "spring steel."
There are dozens of tool steels that can be heat treated to about 48 Rockwell which is spring temper. I don't know of any tool steel that is not weldable. Some like 4140 and 4150 ya gotta pre heat and ramp down slowly or the welds will crack, they will still be strong but cracks no one will pay for.
I'd use a 6011 or 6010 rod and go for it. What's the worst that can happen? Welding will distemper any heat-treated steel in the area of the weld. So the disks my just bend like pretzels afterward.
If you have access to a tig welder friend ask him to do it and try to use as little heat as possible for that purpose, might save the disk

 

[lpakiz]

Well, you name it whatever you want, but when I see a disc blade or a leaf spring, I'm gonna call it spring steel.
And I guarantee that if you weld spring steel and make it hold, it will no longer be "springy" but "bendy"
Thats my story and I'm sticking to it.

 

[Raul-02]

And I guarantee that if you weld spring steel and make it hold, it will no longer be "springy" but "bendy"
Thats my story and I'm sticking to it.

This is correct

 

[WranglerX]

I was told that discs have high manganese content that to preheat area to weld before attempting to weld...

 

[Raul-02]

I was told that discs have high manganes

Manganese is in a lot of tool steels There is a 12% manganese steel called Mangalloy I think RR tracks are made from it. It had a high work-hardening index and is pretty tough but not terribly hard when heat treated. if you want to weld it like the certified welders do you will need to learn a faitr bit start here https://www.risegroup-metal.com/es/news/how-to-weld-high-manganese-steel

 

[BufordBoone]

A new disc was $32. But, it was fun learning! Thanks, to all.

 

[Raul-02]

A new disc was $32.

snookered all of us eh? Now I'm starting to wonder if you really did have that spaceship in the first place.

 

[BufordBoone]

snookered all of us eh? Now I'm starting to wonder if you really did have that spaceship in the first place.

It will be turned into "Garden Art" for the wife.

What it all came down to was the realization that if I did successfully weld it up, it likely wouldn't last long.

I was lucky I was discing a small field and saw it before running over it. Even worse, if I didn't notice it was gone, I could have "discovered" it while riding my ATV.

What was it that old Gambler said? "Gotta know when to hold em and know when to fold em". The responses I got from this forum clearly indicated it was time to fold.

BTW, I took the old blade to the Farmer's Co-Op as an example so we could get the right size. The guy behind the counter took one look and said "Tried to weld it, huh? Disc blades don't weld too well. They always crack".

 

[2manyrocks]

There is some very clever and entertaining Garden Art out there. Good luck with yours. And post pictures.

 

[ROUSTABOUT]

I have welded them. My brother broke one that way. Got another and threw the broke one down. Said it couldn't be welded. That's all he had to tell me. Because I took it and welded it. Welded fine, worked fine.

But in the future, if you get a broke one, weld it up, and weld the center hole up. They make good cooking pots over a fire or fish cooker. Give them to your friends. Weld a couple handles across each other. We use old horse shoes, but we have them around here. You can bend some rod or rebar to make handles.

I also sometimes weld a pipe off the convex side and make a grinder stand, or for any stationary equipment.

That piece you welded, grind it smooth because those collars bolt up against it when you put it on disc. The spring steel, or hardness part, is more about having a tough cutting edge. Put it on the end by the axle nut in case it breaks again. Easier to get to.

 

[Raul-02]

But in the future, if you get a broke one, weld it up, and weld the center hole up. They make good cooking pots over a fire or fish cooker.

Hmmm Loud chimes?

 

[ROUSTABOUT]

Hmmm Loud chimes?

I absitively posolutely can't stand wind chimes. That's why I'm way off the road with woods on three sides of me.

 

[Raul-02]

I absitively posolutely can't stand wind chimes.

So umm I think I guess that's what - - - maybe - - possibly a potential no from you on chimes?