Pros: your response to this opinion?

[Ruark]

On another welding forum, I ran across a detailed post that contained a lot of interesting information about different rods, ratings, numbers, and the rod manufacturing process. It contained some rather unique viewpoints I've never read before, here or elsewhere.

The subject of 7014 has come up here before, and how some people see 7014 as a weak rod, good for sheet metal or thin, non-critical welds, while others swear by it, like the farmer who's been fixing his heavy equipment with 7014 for 25 years and has never had a weld failure.

The "common wisdom" seems to be that 7014 is more brittle and cracks easier than 7018, which reportedly is more malleable. There's a paragraph in this article that address this concept, and I would like to hear from the more knowledgeable people here regarding this information. Here's the paragraph:

"The only weakness that a weld with a 7014 rod would have in comparison to a “professional” 7018 weld, when both rods use the same core metal is….. The 7014 weld will be more susceptible to hydrogen cracking for the first few days till the hydrogen has a chance to permeate out of the welded metal. Once that happens, then the toughness/durability of the weld is exactly the same. In situations where there isn’t much chance of hydrogen cracking (unrestrained/light gauge metal). Then there isn’t really any difference. Most people won’t put something to heavy use within hours of welding it. After the weld has set for a couple days, then there is no chance of hydrogen increasing the chance of breaking from vibration. If it broke with 7014 after a couple days of sitting, it would have broke with 7018, given the same kpsi weld strength."

This would explain why, for example, some people have been able to easily break a 7014 weld with a hammer - they didn't wait a couple of days first - if what this post says is true.

Here is a link to the entire post, if you'd like to read it. In any case, it would be interesting to hear from some of you guys about the comments above regarding 7014.

http://tinyurl.com/blrpyl7

[Lanse]

Im no pro, but it sounds like BS to me. Im no metallurgist and I could be wrong, but IIRC, once steel cools, its cool.

[LarryO]

I thought it takes 28 days for a weld to cure to its full Ksi value.

[mechanic416]

If you are using a EVERLAST welder this may be true

[LarryO]

Watch it!

Luggy will come looking for you with comments like that.

[Bob]

I think it's bull. There is more to consider than the 70 on the front of the rod number. 7018 penetrates better than 7014. 7018 doesn't have any hydrogen get in the metal that needs to leach out which I doubt it would do any way. The elongation factor of 7018 is greater than 7014, meaning it can stretch farther before breaking.Because of this good elongation factor, it will also hold up to more vibration.

Then there is what I know from using 7018's and the strength it has. I once built a bumper for a 1958 Chevy 4x4 truck out of 6" pipe. It was an air tank as well as having a massive drop reciever hitch on it. It probably weighed 250#. I had it in position and tacked it with two tacks at the top and two tacks at the bottom of the channel that was bolted to the frame. I got a call at that time and had to go some place. The guy that owned it came by while I was gone and took it home, thinking I was through. When I called him about it, he was already home, 20 miles of rough country roads and a rail road track to cross. The bumper was still on the truck and only with four 1/4 to 3/8" tacks.

If 7018 is available then use 7018s.

[LarryO]

I'd agree with Bob and call BS on that too.

I thought the only way to get hydrogen out of metal was to heat treat.

Also, the AWS A5.1-91 Carbon Steels Electrode Chart specs 7014 as a low penetrating rod and 7018 as medium penetrating rod.

[nova4353]

Well I'm no pro,but I am one of those farmer types,and while I dislike the 7014 for being a slaggy rod anyplace I ever used it it has done ok. If it broke,was my fault poor weld or a bad choice of rod for the position. I use a lot of 6011 and 7018. As to hydrogen, would not that have a lot to do with the base metal metallurgy? I once used a piece of drill stem as a pivot point pipe, was what I had handy. Pivot point proved to be a real stress point in the design of the grapple I had copied. Quick and dirty design. Long story short, 7014 rod held up ok for bout 6 months then cracking began and fail. 7018 was used with peheat. Held up for a year and a bit. Then I built a different grapple. Point being yes 7018 is better,but had I had a piece of good mild steel pipe I feel 7014 would have done fine. I'll have to read up on hydrogen now....

[Ruark]

LarryO: I looked up AWS A5.1-91 and can't find any such chart, or any such classification of deep or shallow penetration. Could you help me find it? Thanks.

[LarryO]

I'll probably get ripped for this, but here it comes.

My opinion is too many people ( home welders/non pro welders ) look to much into penetration when not necessary. Good joint design and a technically good weld most of the time is more than adequate.

Half of Australian home welding is done with 6013 because that is what most non welding stores sell and most dont know the difference. i.e, Hey, i got some welding rods. Lets weld.

Hard to get 7018, 6010/6011 or anything else for that matter unless you go to a dedicated store. I have seen 7014, 7024 and hardface in some local stores marketed at home welders, but they are only sold in packs of 5 rods and expensive.

Once again, you dont see a lot of weld failures with the exception of bad welds and poor joint design. Even sometimes ive seen quite bad welds do years in service, although im not saying everyone should go out and do Bird welds.


BS over

[LarryO]

Originally Posted by Ruark

LarryO: I looked up AWS A5.1-91 and can't find any such chart, or any such classification of deep or shallow penetration. Could you help me find it? Thanks.

This is a book of Australian CIGweld consumables that also lists AWS stuff in the tech section. Great little guide. I have 2, one in the garage and one beside the computer.

http://www.austwelding.com.au/Techni...ide%202008.pdf

Page 263-264

[Joshfromsaltlake]

All else being equal 7018 H4R tends to have slightly better elongation/ductility and performs better in notch impact tests. That's what I've read anyway. I don't have experience QT'ing stick welds since my company doesn't use stick. We use MIG and gas shielded flux core.

As a side note. MIG and gas shielded fluxcore, if properly managed, produce welds that have better properties than stick in every way.

If you assume a reasonably defect-free weld, properties like impact toughness are going to depend on weld cleanliness, heat input, cooling rates, joint geometry, the amount of restraint, material thickness, et cetera ad nauseum. At least with carbon steel, the choice of fillers is not often the major cause in weld failures.

Although it's reasonable to assume that hydrogen will diffuse out of a weld after a week or two, defects caused by hydrogen when the weld solidifies are permanent. For example, small hot cracks and microscopic porosity.

Hydrogen induced hot cracks aren't a problem in low-carbon mild steels anyway. You have to consider the chemistry of the base metal as well. Hydrogen cracking was a bigger problem 60 years ago when steel companies had a harder time controlling sulfur. A lot of research these days deals with cracking in environments rich in both sulfur and hydrogen.

[Ruark]

After reading that, it would be interesting to repeat that "number of hammer blows" test with some 7014 welds that were, say, 6 hours old vs. some that were a week old, to see if they really were stronger after the hydrogen "permeated out."

[Lanse]

Originally Posted by Ruark

After reading that, it would be interesting to repeat that "number of hammer blows" test with some 7014 welds that were, say, 6 hours old vs. some that were a week old, to see if they really were stronger after the hydrogen "permeated out."

Im sure I could do a test like that... If I did, would y'all watch it? I still have most of a box of 7014 from the last test I did...

[Ruark]

Originally Posted by Lanse

Im sure I could do a test like that... If I did, would y'all watch it? I still have most of a box of 7014 from the last test I did...

Sure, Lanse, that would be great. It's always good to have some kind of concrete evidence supporting or refuting a question, instead of a bunch of old windbags blowing off steam...

I might do it, too - I have a batch of 7014 and some 1/4" pieces. If we both came up with similar results, it would be more meaningful. Wanna go for it? Would you weld it on one side, or both sides?

[kolot]

The only 28 day curing cycles I have heard of refer to Concrete, as far as 7014 I think it is a very good rod when and AC only stick welder is what you have. In my early days the 7018 AC was not readily available and with an AC only machine you could get regular 7018 going flat but out of position was a real pain as it would tend to stick on the arc start or just drop out in the middle of the weld. Might sound pompous but if I welded two mild steel pieces side by side, 1 with DC 7018 and the other with AC 7014 I would invite anyone to beat away with a modest sized hammer on both of them while I just kicked back and drank a few beers.(aside the noise, I might even enjoy watching) Don't think you would find much difference everything being equal. Also my first choice with a DC stick welder would be 7018, and for structural work I would take the AC7014 even over most of the 60 series rods, not talking about pipe of course.
As stated above I don't think hydrogen cracking is as much a problem today as in earlier times with mild steels, and I would think the only way of releasing trapped hydrogen would the through heat or heat treating.

[Broccoli1]

Originally Posted by Ruark

LarryO: I looked up AWS A5.1-91 and can't find any such chart, or any such classification of deep or shallow penetration. Could you help me find it? Thanks.

Not a chart but some info from Miller's site

6012 electrodes work well in applications that require gap bridging between two joints. Many professional welders also choose 6012 electrodes for high-speed, high current fillet welds in the horizontal position, but these electrodes tend to produce a shallower penetration profile and dense slag that will require additional post-welding cleaning.

7014 electrodes produce about the same joint penetration as 6012 electrodes and are designed for use on carbon and low alloy steels. 7014 electrodes contain a higher amount of iron powder, which increases deposition rate. They can also be used at higher amperages than 6012 electrodes.

7018 electrodes contain a thick flux with high powder content and are one of the easiest electrodes to use. These electrodes produce a smooth, quiet arc with minimal spatter and medium arc penetration. Many welders use 7018 electrodes to weld thick metals such as structural steel. 7018 electrodes also produce strong welds with high impact properties (even in cold weather) and can be used on carbon steel, high-carbon, low-alloy or high strength steel base metals.

http://www.millerwelds.com/resources...rticle116.html

More info with a Chart

http://www.esabna.com/EUWeb/AWTC/Lesson3_1.htm

[Broccoli1]

Originally Posted by Lanse

Im no pro, but it sounds like BS to me. Im no metallurgist and I could be wrong, but IIRC, once steel cools, its cool.

"specimens in the "as-welded" condition. This means that the weldment or weld metal is not subjected to any type of heat treatment. Tensile test specimens for all electrode classifications other than the low hydrogen types (E7015, E7016, E7018, E7028 and E7048) are aged at200°F to 220°F for forty-eight (48) hours prior to being subjected to the tensile test. This is not considered heat treatment. It simply accelerates the diffusion of hydrogen from the weld metalwelded with the cellulosic or titania type of electrodes"

From the ESAB link

[Ruark]

Originally Posted by Broccoli1

7014 electrodes produce about the same joint penetration as 6012 electrodes and are designed for use on carbon and low alloy steels.

As a relative beginner, I've found this "penetration" issue to be somewhat curious, as penetration seems so tied to current setting.

You may have read another post I made on 7014 where I was playing with different currents. I ran some beads with 1/8" 7014 at 140-145 AC instead of the usual 125 on 1/4" plate, and if I wasn't very careful, it would quickly burn completely through, although it made a beautiful weld. No doubt, if I had run it at its stated maximum current of 165 amps, it would have melted through that plate like the proverbial warm butter.

So, I have sort of a tongue-in-cheek reaction when I read about a given rod having a given amount of penetration. I mean, how much more penetration can you have beyond "completely through"?