How to weld hardened material?

[Larry Helms]

Hello fokes, I need to weld new tooth holders to the breaker bar of my skid steer bucket,this bar is hardened. How do I go about this, and what rod
should I use ? Thanks

[Phillip Hutchinson]

G'DAY LARRY'when I used to work in the workshop at a dried fruit packing shed we used to make an implement called a "KNIFE" which is still used sometimes to cut off weeds under grape vines,the "knife edge" is a piece of hi carbon steel which was welded together to make a wing shape,this was the welded to a piece of 75x20 mild flat,all I used to do was a root weld so to speak and then 2 welds either side this formed an alloy of the 2 metals.Usind this method I hard virtually zero failure rate.
I used a 275 amp transmig welder with ordinary .9 wire,but if you dont have access to one use 4mm (8 guage) lowhydrogen rods on about 180-200 amps if possible.Happy skidding regards Phillip

[Larry Helms]

Thanks Phillip, I never heard the term " root weld " before but then I'm sure
there are lots of terms from across the pond that I haven't heard before. I
welded a plow once and it looked like a nice job untill I looked at it again later
when I discovered a crack along the weld. Cheers , Larry

[Phillip Hutchinson]

G'day again Larry.
We call the first run a root weld,usually you would put this down with a fair amount of current to burn it in,If ya want to real flash you can grind the holder thingies along the edge so as to have a gap at the edge to fill so you literally undercut the weldon to the parent metal.In theory it should stick on for you.REGARDS Phillip

[LundMachineWorks]

You may want to start you weld with a pre-heat to about 400-500 deg F. Keep it that hot during the weld. After you are done welding keep it hot 1100 deg F for a minimum of 15 min. YOu may have to re-harden the areas, but they should not crack.

[Jim Rankin]

Never saw a cutting edge on a bucket that was so hard it was any problem to weld.

[K D Redd]

Yes to what Jim said. I welded anew cutting edge on a Case skid-steer using 7018 with may old Wisconson THD power Lincoln 180. This skid-steer is used on a farm and he has not broke the edge off yet.

Kent

[Martin Draper]

Mechanic and welder for the Montana Dept. of Transportation and we replace a lot of loader bucket cutting edges.
we use a DC welder and 7018 rod and cut off the old edge,dress the bucket with a grinder and weld in the new cutting edge then hard surface the underneath side of the cutting edge and have never had any problems with the weld or the cutting edge cracking or falling off.
I have an old Hobart AC,Wisconsin TJD engine and always use 7018 AC rod with this and it makes as nice a weld as 7018 on a DC welder.
Martin

[Bill Geyer]

Same here, worked for public schools, replaced cutting edge on buckets and back hoes, and rippers, mounts and shoes. Used 7018 no problems. Yes it is tougher and harder than mild steel, and 7018 will do fine with no special treatment other than cleaning it up with a grinder before you weld.

[dennisinaz]

I have had bad luck welding Bobcat buckets with 7018 without serious cracking. Switched to 11018 and a stainless rod for problems and no more cracks. Preheat might have helped. My suggestion is to try a 11018 or nickel rod like brutus.

Dennis

[DTurner]

I think they use base metal 4140 on the teeth or blades . Or a high mn. If it's High MN do it in a well ventilated area the fumes are no good.

[cbbrink]

I would preheat as stated before and use an 8018b2 rod. I use these on heavy truck frames and they work great. make sure that you get the root burned in good. you could maybe use a stainless rod to do the cover.