cracked weld

[Rusty4242]

OK, I finish stick welding a Northern splitter blade to the base plate and a backing plate with 7018 rods.Preped it well, even chamfered the edges, then I noticed one entire weld bead split right down its whole 6 inches. I did tack everything before welding a whole seam. Did it split because I should have done much heavier tacking? I went over it and put down a couple of slow, heavy beads. Seems to have taken care of the problem. Thanks, Larry

 

[jimgerken]

Sounds like cooling shrinkage cracking to me. Sometimes if the stress has no where to go, it will crack the weld. If both parts had been hotter it might not have happened. Otherwise, Weld an inch, stop, let it cool somewhat, then go to the other side and weld an inch, pause for cooling, back to first side, skip an inch and weld an inch, let cool, back to other side, skip an inch weld an inch, etc.

 

[Rusty4242]

Thanks, Larry

 

[Egon]

Are you sure you are using the correct rod??

 

[RonL]

My recollection is that those blades are standard A36 steel plate that is one inch thick. Probably needed pre-heating. Are the electrodes fresh? Low hydrogen rods need to be kept in a rod storage oven once they are opened. I fact, the reason you use low hydrogen rod is to lay in multiple stringers on heavy fabrication. Hydrogen causes the steel to become brittle. 7018 should be the correct rod to use in this situation. I believe Northern recommends this for this application.

RonL

 

[Egon]

My source says maybe a 6011 or so rod would make a difference.

 

[RonL]

Just read your "6011 instead of 7018" thread.

Not to sound like a "Madreferee" post but you may want to do a search on one of the welding sites with this question. "Mad" was right on with this advice.

Miller, Lincoln, and Esab have tons of information in their knowledge bases.

There is much more to welding and metallurgy than simply melting two pieces of steel. Good Luck.

RonL

 

[CRAFTBENDER]

My recollection is that those blades are standard A36 steel plate that is one inch thick. Probably needed pre-heating. Are the electrodes fresh? Low hydrogen rods need to be kept in a rod storage oven once they are opened. I fact, the reason you use low hydrogen rod is to lay in multiple stringers on heavy fabrication. Hydrogen causes the steel to become brittle. 7018 should be the correct rod to use in this situation. I believe Northern recommends this for this application.

RonL

A36 is low carbon hot rolled steel. Maybe the cutting edge has a hardened edge welded on.

 

[Egon]

Well maybe a 6013 rod then seeing as it was cleaned up good!

In actuality welding is merely melting two pieces of metal.

Oh where oh where is Thingy in time of need?

 

[RonL]

Egon

You are absolutely right! Welding is merely the melting together of metal. Getting the desired results may be a little more complicated.
The Northern site has two listings for splitter wedges. One still lists it as being A36 steel and recommends using 7018. The other simply states that it is "1045 hardness".
I am by no means an expert, but I would think that welding a 1 inch thick piece of any type of steel to a beam would entail using pre-heat and some type of low hydrogen rod.
For the price that Northern charges, I think that the wedges are simply a solid chunk of steel. I don't think they could afford to weld on a piece a tool steel for that price.

RonL

 

[Willl]

But, without seeing his weld(s), we're just guessing.

 

[Egon]

As was mentioned I did do some consulting!!

if that wood splitting wedge came in to the shop I would of welded it with 6011 5/32 DCEP and cranked the heat up for maximum penetration. 7018 will stick the wedge to the beam but it wouldn't be my first choice or even a consideration. Now if I wanted to get a little exotic I would probably use Cronaweld 375 5/32 at about 170 amps DCEP. But I save that stuff for cracked excavator buckets and dozer blades.
Sometimes what the specs in the book say is contrary to what the real world demands.

There was also mention of lack of penetration.

A picture would be nice and could tell the tale!

 

[RonL]

Toolboxtalk -> Woodsplitter

 

[toolaholic]

7018 is fine ,I welded ,as a cert. welder in the union for years. We can't make any calls with no info. You're getting blue smoke, from someone that knows very little of welding.

 

[Gizmo2]

OK, I finish stick welding a Northern splitter blade to the base plate and a backing plate with 7018 rods.Preped it well, even chamfered the edges, then I noticed one entire weld bead split right down its whole 6 inches. I did tack everything before welding a whole seam. Did it split because I should have done much heavier tacking? I went over it and put down a couple of slow, heavy beads. Seems to have taken care of the problem. Thanks, Larry

You used the correct rod. Using this rod you need a lot of heat and you should have put down 3 passes on each side. Tack each side really well, run a pass down the first side then the other side, let it cool slightly, need to chip anyway, add another pass to the first side then the other side and so on. Don't play games waiting between passes on opposite side, as it WILL pull.

 

[toolaholic]

Rusty ,I don't come to this forum much and Your project is probably completed.
A lot of Us over at weld talk are Cert. welders with x ray papers. We love to help. Let us take a look at your weld,if It's still around. I've welded many 3 ft. 1 1/2" flange I beams with 7018. Sounds like You were way to cold ,and had no peneration. Also if rods wern't dry You might have hydrogen embrittlement.
I;m toolaholic over at [url=http://www.hobartwelders.com/weldtalk

 

[Renze]

How did you weld it ?

from top to bottom, or a horizontal under hand weld ?

With wire welding in vertical position, a common problem is a phenomena called "sticky welding" e.g. you start welding top down, the melting bath is too hot so it doesnt burn in the mother material but starts sinking down, just sticking to the workpiece but not burning in. When that happens, you have a weld that's just burnt into the mother material on the spot you started the weld, and gets its electrical circuit from there. Then what you're doing is welding "on top of" the mother material, instead of burning into it.

I think in some occasions it can also happen with rod welding, when welding with high current, and with some paint or rust on the workpiece.
I had it in the past (before i had a mig) with rod welding on galvanised hog stables.

I dont know how you welded it, vertical or horizontal, but i think anyone can use the information

 

[Egon]

That's good Ron.

I had a nice nap after lunch. Started dreaming of steel and all the different variations of it and what these variations showed in the end result steel. After getting into crystal structure and nodular carbon and other such minor details as trace metals I switched over to some of the jobs I was on where welding was required. These jobs required the welder to pass a certification test just prior to being hired! And then darned if we didn't go out and take pictures of his welds while he was on the job! And if we didn't like them they had to be redone. And yea, he even had to use different rods on different parts of the weld.

Attached is a picture of the type of welds I was used to looking at but its not the type of picture we took. The other picture is of the welder!

 

[RonL]

Gosh Egon, You are just the sweetest!

Your other face is interesting. But at least TBN members got a glimpse of what you really think of them.

RonL

 

[Egon]

I must have told the truth somewhere and you got all excited when I did not listen properly ehh what; old chap!