Cast iron to AR plate welding gone wrong

[tbirkey214]

So I got this cast iron base that had some weird diamond plate brace to it and a bench grinder on it. I checked the bench grinder cuz it was garbage and I'm trying to use this for my big vise. I bought some 4x8 plate off of some dude way out in the country and I'm pretty sure that this is AR plate because it's impossible to drill into so now I got all this time into this cast iron base in this AR top plate and I'm trying to make this work. I bought some super missile weld rods which are part nickel and used for cast iron, and I clean this thing up real good and got my rose bud out of my torch and heated it up for like 20 minutes and I could just kind of barely get it to go back and forth from glowing red and I figured I'd be good enough so I use the super missile rod and it was very nasty but I've let this thing cool for about 3 hours I called it down with the torch until it was just kind of hot and I saw the plate was bent so I hit it with a hammer and it broke right through the weld.

Was I supposed to let this thing cool overnight, is because I hit it with the hammer, or maybe I didn't get this thing hot enough. I laid on that torch for a while until it seemed like it wasn't going to get any hotter, but I tried to braise it with some lfb rod and I just could never get it hot enough to melt into the joints so I'm curious which part went wrong? I can't imagine I was supposed to let this thing cool till morning, am I right in assuming that's too long to let cast iron cool to make it crack like that?

Single let me add pictures, but it busted right through the center of the weld

 

[nadogail]

If the plate is 4' by 8' You may not have had enough Pre Heat

 

[tbirkey214]

If the plate is 4' by 8' You may not have had enough Pre Heat

The sheet i bout was. Im welding a 3/8 thick about 12 inch in diameter circle to a 5" in diameter tubular section of an old lamppost(or sommeth8ing?)

 

[MoonRise]

https://www.lincolnelectric.com/en/welding-and-cutting-resource-center/welding-how-tos/guidelines-for-welding-cast-iron

Cast iron to AR plate? Oh boy.

General procedure for welding cast iron is to use preheat and lots of it, slowly and evenly. Depending on the size of the cast iron, you might be preheating to 700-1200F (see above article). Then weld using high nickel electrodes (Ni99 aka $$$$$ rods, or Ni55 $$$ rods if machining after welding is not needed), minimize admixture, back into the oven or furnace and slow cool at about 100F per hour (or other ways to let the parts cool down that slowly). Yeah, that means overnight usually, 12+ hours cooling.

SuperMissile rod is not really high enough in nickel for welding cast iron IMNSHO. It's usually a variant of 312 stainless, which is about 9% nickel and 30% chromium. Handy (if expensive and sort of proprietary), but not what I would choose for welding cast iron. Because all that chromium is probably going to mix with all the available carbon from the cast iron (usually about 4% Carbon) and make hard brittle chromium Carbide in a chromium-nickel-iron matrix.

BTW, how did you cut your disc of AR plate out of the big sheet of AR plate? Thermal methods can affect the properties of AR plate.

 

[MoonRise]

Three Common Challenges of Welding Abrasion-Resistant Plate, and Their Solutions

Learn about welding abrasion-resistant steel plates and how to address unique challenges for efficient welding processes.

www.hobartbrothers.com

7 Tips for Welding Abrasion-Resistant Plate | Modern Contractor Solutions

7 tips welding abrasion resistant plate. These 7 tips will help walk you through the process of welding abrasion resistant plate.

mcsmag.com

 

[tbirkey214]

https://www.lincolnelectric.com/en/welding-and-cutting-resource-center/welding-how-tos/guidelines-for-welding-cast-iron

Cast iron to AR plate? Oh boy.

General procedure for welding cast iron is to use preheat and lots of it, slowly and evenly. Depending on the size of the cast iron, you might be preheating to 700-1200F (see above article). Then weld using high nickel electrodes (Ni99 aka $$$$$ rods, or Ni55 $$$ rods if machining after welding is not needed), minimize admixture, back into the oven or furnace and slow cool at about 100F per hour (or other ways to let the parts cool down that slowly). Yeah, that means overnight usually, 12+ hours cooling.

SuperMissile rod is not really high enough in nickel for welding cast iron IMNSHO. It's usually a variant of 312 stainless, which is about 9% nickel and 30% chromium. Handy (if expensive and sort of proprietary), but not what I would choose for welding cast iron. Because all that chromium is probably going to mix with all the available carbon from the cast iron (usually about 4% Carbon) and make hard brittle chromium Carbide in a chromium-nickel-iron matrix.

BTW, how did you cut your disc of AR plate out of the big sheet of AR plate? Thermal methods can affect the properties of AR plate.

A cut off wheel. I didnt think it was AR at first because it cut decently and grinds decently but it ruined my center punches and about 10 drill.bits... it would drill about a 64th and then squeeze. I could be wrong but I have never had this happen

 

[johninct]

So I got this cast iron base that had some weird diamond plate brace to it and a bench grinder on it. I checked the bench grinder cuz it was garbage and I'm trying to use this for my big vise. I bought some 4x8 plate off of some dude way out in the country and I'm pretty sure that this is AR plate because it's impossible to drill into so now I got all this time into this cast iron base in this AR top plate and I'm trying to make this work. I bought some super missile weld rods which are part nickel and used for cast iron, and I clean this thing up real good and got my rose bud out of my torch and heated it up for like 20 minutes and I could just kind of barely get it to go back and forth from glowing red and I figured I'd be good enough so I use the super missile rod and it was very nasty but I've let this thing cool for about 3 hours I called it down with the torch until it was just kind of hot and I saw the plate was bent so I hit it with a hammer and it broke right through the weld.

Was I supposed to let this thing cool overnight, is because I hit it with the hammer, or maybe I didn't get this thing hot enough. I laid on that torch for a while until it seemed like it wasn't going to get any hotter, but I tried to braise it with some lfb rod and I just could never get it hot enough to melt into the joints so I'm curious which part went wrong? I can't imagine I was supposed to let this thing cool till morning, am I right in assuming that's too long to let cast iron cool to make it crack like that?

Single let me add pictures, but it busted right through the center of the weld

What is AR?

 

[manwithtools]

What is AR?

See post #5

AR = Abrasion Resistant

 

[johninct]

See post #5

AR = Abrasion Resistant

Would you weld AR on a backhoe bucket?

 

[manwithtools]

Would you weld AR on a backhoe bucket?

That is one of the most common uses of AR plate.

 

[cannuck]

Dusting off my dim memories of days around welding rods: the major problem is the chrome in the rods. Iron and nickel just fine, but the Cr around cast Fe makes Chromium carbides that are as brittle as all getout. Now, if I was selling expensive rod to a company that didn't care about the price, I would go 99 Ni. If I was to tell you I have seen such things welded successfully with 7018 I would expect the derission that is sure to follow but just sayin'.

 

[badmatt]

Welding AR it self, is a non issue.

The cast iron on the other hand. a lot of variables.

We weld durabar 80-55-06 to mild steel often and utilize 309 filler with GMAW. Cleanliness is key.

For post cooling you can try getting a pail and filling it with vermiculite and tossing it in immediately after finishing the weld and covering it up or wrap it in an batt of fiberglass insulation as tight as you can and taping it up. leave it to the next morning.

as for preheating - tack the joint up and heat the cast iron to 500F check it with temp sticks.

But at the end of the day, how important is this cast iron base?

 

[txvwnut]

What about brazing the two together?

 

[niget2002]

My welding skill **** compared to most people. I think I'd be looking for a way to modify the base so that I could bolt the top plate to it.

 

[MoonRise]

Option: weld some mounting ears/tabs to the bottom of the AR plate and bolt that to the cast iron tube/pipe.

 

[tbirkey214]

I also dont want to

Dusting off my dim memories of days around welding rods: the major problem is the chrome in the rods. Iron and nickel just fine, but the Cr around cast Fe makes Chromium carbides that are as brittle as all getout. Now, if I was selling expensive rod to a company that didn't care about the price, I would go 99 Ni. If I was to tell you I have seen such things welded successfully with 7018 I would expect the derission that is sure to follow but just sayin'.

I have heard this ALOT since digging around on the web for my question. Works just fine everytime their saying.

This IS a base for a vise, so it is going to have to endure some beatings, but most seasoned guys are saying in a pinch it has always worked

 

[tbirkey214]

Welding AR it self, is a non issue.

The cast iron on the other hand. a lot of variables.

We weld durabar 80-55-06 to mild steel often and utilize 309 filler with GMAW. Cleanliness is key.

For post cooling you can try getting a pail and filling it with vermiculite and tossing it in immediately after finishing the weld and covering it up or wrap it in an batt of fiberglass insulation as tight as you can and taping it up. leave it to the next morning.

as for preheating - tack the joint up and heat the cast iron to 500F check it with temp sticks.

But at the end of the day, how important is this cast iron base?

Like as far as how important it is to ME? It just looks cool so I wanna do it.

Should I grind out the old supermissle weld completely or can I groove it and put the nickle rod ?

 

[tbirkey214]

What about brazing the two together?

I went and bought some lfb rod and tried to braze it but I just couldn't get the workpiece hot enough. It's a foot in diameter of 3/8 AR plate on top and then a pretty beefy cast iron base. I heated it up for about 15 minutes and then said screw this

 

[cannuck]

I also dont want to

I have heard this ALOT since digging around on the web for my question. Works just fine everytime their saying.

This IS a base for a vise, so it is going to have to endure some beatings, but most seasoned guys are saying in a pinch it has always worked

You still want to preheat and slow cool, though

 

[badmatt]

Like as far as how important it is to ME? It just looks cool so I wanna do it.

Should I grind out the old supermissle weld completely or can I groove it and put the nickle rod ?

Id grind out all the old weld and any visible cracks.

 

[MoonRise]

Remove ALL of the old, cracked, or iffy weld.

Clean the AR plate to bright clean shiny steel. Follow the hints and suggestions in the two links that I posted above about welding AR steel. Weld brackets/tabs to the AR plate. Use those brackets/tabs to bolt the plate to the cast iron post.

Remember that any and all loads from your vise activities be going to that cast iron post. So try to make sure that the welds, brackets/tabs, and bolting layout are up to the task.

 

[ATC]

I weld a lot of ****, but I don't touch cast stuff for this reason. Good luck!

 

[PWC Repair]

This might sound silly but I've welded cast iron MULTIPLE times with my flux core wire welder. I have an old chevy 350 block sitting here with probably 4-5 FEET worth of welds on it that I've been playing with. I welded up the broken pulley on my wife's grandpas antique cement mixer years ago and it's mixed quite a few bags since then.........pulley still good! If the weld needs added strength I braze in some 6% silver rod for HVAC use WHILE I'm welding with the flux core.

 

[tbirkey214]

This might sound silly but I've welded cast iron MULTIPLE times with my flux core wire welder. I have an old chevy 350 block sitting here with probably 4-5 FEET worth of welds on it that I've been playing with. I welded up the broken pulley on my wife's grandpas antique cement mixer years ago and it's mixed quite a few bags since then.........pulley still good! If the weld needs added strength I braze in some 6% silver rod for HVAC use WHILE I'm welding with the flux core.

What kind of flux core wire?

 

[PWC Repair]

What kind of flux core wire?

Plain old .030 for mild steel.

 

[tbirkey214]

Plain old .030 for mild steel.

Heat treat, peen, pray to the gods, or just rip it and it never cracked?

 

[PWC Repair]

I DO put a small amount of preheat in. Just wave the standard propane torch on the area until warm. Weld 'er up.........and use the slag hammer to peen for several minutes as it cools down.
I used this technique WITH the silver rod to weld up a cracked main saddle on a chevy smallblock recently. It was then tanked, shot peened, and baked at the machine shop and passed the magnaflux test. The machinist also wanted to know EXACTLY how I welded that up. I have pics of that repair here somewhere.