Can 8018 and 9018 welding rod be used in lieu of 7018?

I have a few unopened cans of 8018 and 9018 welding rod.
Can I use them freely like I would 7018? They are stronger, is that
going to create any cracking?
Reply to
Ignoramus8242
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7018 is a low hydrogen rod. If you do not keep it in a rod oven after opening the can, it will absorb water and cause cracks in high strength steel. But can be used on low strength steel like any rod with hydrogen.
My understanding is 8918 and 9018 are also low hydrogen rods. Can only be used on high strength steel if kept water vaper free, but can be used on low strength steel regardless.
Dan
Reply to
dcaster
Check Hobart:
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...oor Lincoln Electric:
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Compare the elongation figures.
Reply to
Ed Huntress
I have a WHOLE BUNCH of this in VERY old unopened cans. Do you think its still any good? I can dry it in the oven
Reply to
Karl Townsend
That was my experience as well.
The question is will welds of regular mild steel be "sound".
i
Reply to
Ignoramus8242
The welds in mild steel will be sound even if the rods have been exposed to the air and are not good for low hydrogen welds.
Dan
Reply to
dcaster
Dan, what I mean to ask, will welds of MILD STEEL be sound if I perform them with 8018 or 9018 electrode, as opposed to 7018.
i
Reply to
Ignoramus8242
The test we learned for that was to make a butt weld between two pieces of scrap, grind the beads mostly flat and then bend the seam over double along the weld line. 1/8" steel was bent with a hammer in the shop vise and they had a 50 ton press for heavier pieces.
Try it with a single unwelded piece of steel first to see how or if it cracks. We were practicing on mixed scrap from a fab shop, mostly plasma torch cutouts.
--jsw
Reply to
Jim Wilkins
It depends on what you mean by "sound", and what the geometry of your weld is. Your 8018 and 9018 welds will definitely fail at lower deformation than a 7018 weld, and cracking will be more likely, but not necessarily a problem. In all cases I have seen where 9018 was required, preheat to 400-500F was also required, but these were multi-pass welds on ~2% chrome-molly steel. Why not try a few welds and give them the hammer test?
If there is a 3-letter code after the xx18 designation your rods are probably special purpose, such as for chrome-molly, and a preheat requirement (or a brittle weld) is more likely.
While the rods might work for your purposes, for any critical weld on structural steel, where failure would cost a lot or possibly hurt someone, I would use 7018 even if I had to go buy it.
Reply to
Glen Walpert
You have this posted in SEJW so Ernie ought to comment. But as I understand it, you should be fine using 8018 or 9018 on mild steel.
Dan
Reply to
dcaster
OK, thanks a lot...
Reply to
Ignoramus12525
Looks like I will stick to my original use...
I take a bolt biter and cut both ends at an extreme angle to make a point. Then use it as a tree spreader to bend apple tree limbs down.
Reply to
Karl Townsend

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