Cast Steel

[Allen]

I answered some questions on JU regarding welding a center section or cast steel.

I'm not typing this twice so here's a cut and paste. This is strictly FYI. Some of it might not make sense unless you read the thread on JU, but you'll get the gist.

Allen

The bottom line is this:

To properly weld cast steel, you must know the manufacturing process used to create it and whether or not it was heat treated in any way. The chemical composition of the steel is also a big help.

Because that's an impossibility to determine or find out in the vast majority of cases, I'll cover what my experiences have been with cast steel parts, which number now in the thousands that I've welded. Besides cast, I've welded on more heat treated steel than I care to re-live.

And remember.....cast steel is not cast iron. (The majority of specialty rods for joining cast iron to steel, were developed because of the cast iron. Not because of the steel. The above mentioned Royal 260 electrode is for welding mild steel to cast iron, but the process described is for repairing a crack in cast iron.....)

Do you preheat cast steel? Sometimes.....It isn't always necessary. So how do you know? You don't. But here's the thing, preheating never hurts! Provided.....you only go to 450*F or so. Any lower, why bother? Any higher, you run the risk of damaging the grain structure of the casting and setting up a weak point. So, preheat whenever possible.....400-450*F is perfect, especially if you aren't real sure of what you're doing. The reason you preheat is so the weld and the part cools slowly. This helps reduce stress. Cast steel generally doesn't need to be peened.....I've never seen it done.....cast iron is a different story. Cast steel can usually air cool, requiring no post heat. Cast iron is a different story, often needing to slowly cool in an oven for hours.....Your weld supply shop should have temperature sticks for a couple of bucks. Buy a 450* stick. It will melt on the part if the temperature is at or over 450*. They should have them in 25* or 50* increments from 200* to 700*+.

Do you have to use a high nickel rod on cast steel? No. Does it hurt if you do? No. The reason the high nickel content rod is used is to reduce weld warpage/shrinkage which places stress on the cast part as the weld "pulls" the base metal together. The high nickel content relieves the weld shrinkage. Nickel doesn't shrink much as it cools. The high nickel rods are for cast iron, where this reduction in stress is very important. It isn't as important in cast steel. Cast steel is no where near as brittle as cast/nodular/grey/or white iron.

Can you MIG weld cast steel? Yep. Would I? Only if I didn't have an arc welder around. MIG welding is awfully stressful, throwing a lot of heat into the part. A stick electrode with it's flux coating will allow the weld to cool more slowly, plus, it throws less heat into the part. Now this is very nitpicky and subjective. This is really where you get into the manufacturing specifics of the cast steel. I've seen cast steel welded with high deposition MIG.....which is MIG usually running two wires instead of one (although it can be a single wire process) at insane wire speeds and voltages. Preheat runs 50-50. About half the time I've seen it preheated.....half not. I've also seen cast steel just plain old MIG welded.....but it's usually been preheated. But not always. Usually cast steel in my experience is sub arced, which is an automated wire feed process, but with a flux agent similar to sand that completely submerges the arc so you can't see what is going on. (A bitch to learn because you can't see the arc.....you have to know before you even start how what you're doing will affect the weld and how it will look. But once you learn, the welds can be beautiful.....if you care.) This produces a slag which must be removed. It's similar to flux cored wire feed welding. (gasless MIG; which isn't the correct term but I'm using it for a description's sake)

So there you go. Clear as mud, huh? Now you know why when you ask you get a different answer from everyone.

What would I do?

Preheat.

DC stick weld with a high nickel rod.

If I was lazy I'd preheat and DC weld with likely, Low-Hy.

If I was really lazy, I'd preheat and MIG. (Do not run out and buy a stick welder just because it's something I wouldn't do. It's not that I wouldn't do it, it just wouldn't be my first choice, that's all. If you've had success in the past MIGging cast steel.....stick with it.)

For the guy that didn't preheat but turned up the voltage to compensate, don't do that. You might have gotten away with it, but that's the worst thing you could do. If that had been cast iron you'd of had a disaster. And most of the time.....don't weld a little at a time. Weld it completely. Provided you know how to compensate for, or how to control warpage. Welding stresses metal. The more you weld, the more stress. The more heating and coolig cycles you subject your base metal to, the more stress you introduce.

Hope this helps, but it'll probably just cause more confusion and disinformation.

[Krash80]

Nice...now i have a written copy of the short lecture i got this weekend that went in one ear and out the other.

That was a helpful paragraph, but you do realize that when i get a hp44 to chop down that i'm still going to beg and plead till you weld my knuckles on for me....or at least bribe you with beer.

-Ron-

[Allen]

Originally posted by Krash80
Nice...now i have a written copy of the short lecture i got this weekend that went in one ear and out the other.

That was a helpful paragraph, but you do realize that when i get a hp44 to chop down that i'm still going to beg and plead till you weld my knuckles on for me....or at least bribe you with beer.

-Ron-

In one ear and out the other? I know you were excited to see me, everybody is, but please, when I speak, LISTEN.

Dang.....a "couple" of beers and suddenly I'm an alkyholic that can be bribed with beer.

Allen

[mrblaine]

Originally posted by Allen
In one ear and out the other? I know you were excited to see me, everybody is, but please, when I speak, LISTEN.

Dang.....a "couple" of beers and suddenly I'm an alkyholic that can be bribed with beer.

Allen

I can be bribed with jeep parts.

[Allen]

Originally posted by mrblaine
I can be bribed with jeep parts.

I have some bumper end caps and a full set of tan carpet (lightly soiled) from my '97. Where should I ship them?
Allen