Bending a bucket cutting edge.

[4570Man]

Or couldn't a guy just heat it to red and quench in oil? This is a slower quench that toughens the metal, but avoids brittleness. I've done it a number of times and had excellent results.

Doesn't the oil catch on fire?

 

[Renze]

Nevermind. A weldable cutting edge is wear resistant because of the alloy, not because of the heat treatment. There simply isnt enough carbon in weldable steel to change the characteristics of the steel by heat treatments: You can only release inner material tension from cold forming or welding by heat treating it, but not change the hardness.

Welding itself is a heat treatment. If the steel had enough carbon to make it hardenable, it would be not (or hardly) weldable because welds that are cooled rapidly by the surrounding material, (or actually the HAZ) would become brittle.

 

[2458n]

I think if you put your oil in something like a old piece of eve spouting,,,, one oil change on your truck should be plenty. The cutting edge is a wear item that lasts
a very long time.

 

[bigdeano]

This is an old county grader blade I heated and bent. I didn't quench it. I used to use the left corner to gouge crushed rock out of a road cut, so it's kind of beat up, but it's been on there for 35 years. A file just slides on it where it wasn't heated. I welded it with stainless rod.

 

[Walker1]

Doesn't the oil catch on fire?

Yes, it does. Mostly just burns on the surface and generally goes out when you pull the hot iron out. It is a stinky dirty mess regardless. I usually try to avoid using it.

 

[CNC Dan]

Welding itself is a heat treatment. If the steel had enough carbon to make it hardenable, it would be not (or hardly) weldable because welds that are cooled rapidly by the surrounding material, (or actually the HAZ) would become brittle.

I dissagree, in part.
You can weld high carbon steel. But you must take steps to prevent embrittlement and cracking. Pre-heating is the most common. If all the steel is hot, it won't pull heat from the weld, so the weld won't be quenched and hardened.

And then there is heat-treating. After welding and/or bending the whole piece is heated to its transition temperature. Then quenched(cooled rapidly). Now the piece will be hard and brittle, so it is then tempered. Tempering involves re-heating to to a specific temperature to un-do some of the hardening, making the piece less hard, but more tuff than it was after quenching.

Not likly any of us have the ability to heat treat a large piece like an entire cutting edge at home, but some good pre-heat might keep a weld from failing.

 

[Renze]

Not likly any of us have the ability to heat treat a large piece like an entire cutting edge at home, but some good pre-heat might keep a weld from failing.

Thats the exception to the rule. As a rule, bucket edges that are "weldable" arent high carbon.
I repaired cast iron things too by preheating, stress peening and post-heating the area around the weld. But as for the OP, he can just weld ahead and dont worry about heat treatment.

 

[PILOON]

Heck, what I'd do is cut 1/2 way thru along the width, heat and bend and then I'd weld the cut side closed with maybe 2 passes.
That way I'd have a tight 90 deg bend and still retain the temper of the edge.