7018 Vs. 7018AC, Need Layman's translation please:

[shade tree welder]

They are mild steel, do not fool yourself into thinking they are anything else.

by the second picture you did not bevel them near enough you have no
penetration into the parent metal at all.

Regrind a heavy bevel reweld with 6011

 

[Shield Arc]

It sure looks like cast steel to me. I would double bevel each piece. Us a piece of angle iron clamped to both pieces for alignment, preheat to 300 degrees. You can use 312 stainless steel or a rod called Super Missile Weld, but it is basically 312 stainless steel. You won't like the cost of either one of these! I have welded countless items made of cast steel with plain old 7018. Post heat is the trick here, wrap with insulation.

 

[shade tree welder]

Butt joint preparation.

 

[Shield Arc]

If they are indeed mild steel, you can do everything I said in an my earlier post except you won't need so much preheat, or postheat.

 

[Big Wave D]

I need a little further explanation of proper way to bevel.

I double beveled both halves down to a heavy 1/16th of original material touching. My bevel was over 45 degrees as well.

It didn't break in the same place either. It was close but different.

I will definitely use heat this time and go with some 312.

Any comments or suggestions about adding some reinforcements anywhere and how best to accomplish that.

 

[shade tree welder]

It sure looks like cast steel to me. I would double bevel each piece. Us a piece of angle iron clamped to both pieces for alignment, preheat to 300 degrees. You can use 312 stainless steel or a rod called Super Missile Weld, but it is basically 312 stainless steel. You won't like the cost of either one of these! I have welded countless items made of cast steel with plain old 7018. Post heat is the trick here, wrap with insulation.

Really you think they used cast steel on a King Kutter brand "Bush Hog"
for the 3 point frame. You might want to look a little closer on what broke
and where it broke. See my modified picture.

 

[Shield Arc]

Really you think they used cast steel on a King Kutter brand "Bush Hog"
for the 3 point frame. You might want to look a little closer on what broke
and where it broke. See my modified picture.

Ron I was just going by the picture. But now I too believe they are mild steel, but you got to admit that's some nasty looking steel / break. :confused2:

 

[Big Wave D]

Shade Tree Welder or anyone else,

I gather from your comment, I produced a 'cold' weld, which is highly possible.

With 1/8th inch 312 rod, what would you say amperage-wise I should be using?

 

[shade tree welder]

Lack of penetration is the problem very clear in this picture. I see little
evidence of beveling. The yellow lines show the limit of penetration, does
not matter how much preheat, fancy super duper rod or post heat you use.
You have lack of fusion, it will fail.

 

[shade tree welder]

Shade Tree Welder or anyone else,

I gather from your comment, I produced a 'cold' weld, which is highly possible.

With 1/8th inch 312 rod, what would you say amperage-wise I should be using?

Do not use stainless rod 6011 will be perfect for this
repair 90-100 amps for 1/8".