Welding Certification test Q&A and tips and tricks
andygmac
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Cheers Jonathan, I think I'll just do a couple of full length tests, just to get the travel right, I've only been doing 200mm runs but the test has to be 350mm minimum .
Incidentally, what is your opinion of the travel speed in the procedure? I'm having trouble on the fillet, the procedure states a 6mm(1\4 inch) weld, but with the volts/amps/ sickout/travel speed, I can't seem to get it down to that size, maybe if you have a spare moment perhaps you could have a quick go with those settings and see what you think ;)

Cheers
Andy
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andygmac wrote:Cheers Jonathan, I think I'll just do a couple of full length tests, just to get the travel right, I've only been doing 200mm runs but the test has to be 350mm minimum .
Incidentally, what is your opinion of the travel speed in the procedure? I'm having trouble on the fillet, the procedure states a 6mm(1\4 inch) weld, but with the volts/amps/ sickout/travel speed, I can't seem to get it down to that size, maybe if you have a spare moment perhaps you could have a quick go with those settings and see what you think ;)

Cheers
Andy
Andy,
I would be more than happy to give it a go tonight and see what happens. Now to convert everything out of mm :lol: thankful for google! Will report back when I get a chance.
-Jonathan
andygmac
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Thanks Jonathan, appreciate that :D
Andy
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Andy,
I went out to the garage and switched my MIller 252 over from self-shield flux core to .045 to run a few beads tonight, didnt get very far when I realized your 1G specs fall right into our WPS. Here is a thread that has a picture of a 1" AWS D1.1 1G test I did a few weeks ago to hold you over for now. Also I only have 75/25 in the garage right now anyway.
http://forum.weldingtipsandtricks.com/v ... 7&start=30
Here are the WPS settings for this particular test; ER70S-6 .045, 26-26.5 volts, 280-300 ipm and 240-260 amps, 90/10 gas @ 29-40 CFH, stick out 1/2"-3/4" and I cant remember the travel speed, will fill in that blank in the morning.

I will run a few fillets tomorrow when I get a chance for you. I have two more questions. What is the gas mix percentages you are using and is it only the fillets you are having trouble with?

Oh yea, when I came in I realized why my welder was not acting correctly, I still have it set on DCEN for the flux core. :oops:
It happens.
-Jonathan
andygmac
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Cheers Jonathan,
The gas is 7% Co2 2.5% O2 rest argon.
I was just finding it hard to get a 1/4 inch weld on the fillet at that travel speed
Ill see if I have a spare hour or two tomorrow and try again lol
Or I'll just up the speed a little on the final procedure lol

Those welds of yours look great :-) I hope mine look like that on Monday ;-)

Agh we all forget the polarity occasionally lol

One more thing ;-) the inspector may want me to stop and restart, do I do the same as mma, start in front, pull the weld over the crater, then continue? Or just start on the crater? Or grind it back and restart?
Sorry for all the questions, but I don't want to fail, it would be a very expensive failure lol. Best to cover all bases :-D

Cheers
Andy
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andygmac wrote:Cheers Jonathan,
The gas is 7% Co2 2.5% O2 rest argon.
I was just finding it hard to get a 1/4 inch weld on the fillet at that travel speed
Ill see if I have a spare hour or two tomorrow and try again lol
Or I'll just up the speed a little on the final procedure lol

Those welds of yours look great :-) I hope mine look like that on Monday ;-)

Agh we all forget the polarity occasionally lol

One more thing ;-) the inspector may want me to stop and restart, do I do the same as mma, start in front, pull the weld over the crater, then continue? Or just start on the crater? Or grind it back and restart?
Sorry for all the questions, but I don't want to fail, it would be a very expensive failure lol. Best to cover all bases :-D

Cheers
Andy
Andy,
I didnt get to run any beads today but the good news is I can duplicate your weld to a "T" as I have the same gas you are testing with. Last question for you is how thick is the material on the fillet weld? My machines are either set up for .035 or .052 so I will have to switch out wire and run them. I will use our DC600 as this is what the gas is on.
Personally, I do not know why the inspector would want you to stop and restart on a mig test unless he is just testing your skills. You could grind the stop out a little and start back on the crater, filling it flush with the previous weld and move on. I would be afraid if you started ahead and backed up you would have a chance for lack of fusion because you would just be riding over molten metal. I would like to hear what others have to say about this one as well. One thing to consider is this portion will not be included in the bent test so you should be good. I guess unless it is x-ray. :o
I heard a saying a long time ago that went something like this "show me a weldor that has not failed a welding test and I will show you a weldor that has not taken many tests". This is not ment to discourage rather to show that we all fail tests at one point or another. I failed my first 3G 7018 stick test, kinda embarrassing because my instructor at the time was getting ready to hire me for some part time work and he was "bragging" on me.
If you get the chance to put down a few more beads let us see. I dont think you have anything to worry about though.
-Jonathan
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Andy,
Ok I ran a bead as close to your settings as I could. Ended up running off the 350MP. Used the same gas @35cfh, .045 wire, 26volts, 425 wire speed and achieved around the 260 amps in your WPS. I timed my travel at roughly 12 inches per minute. I was able to get a 1/4" fillet but the top is a little to hot. You will have to move to achieve that 1/4" fillet, any slower and you will exceed your specs. I did not do a macro etch test as I do not have anything here to do it with. I hope this helps and if not just let me know.
-Jonathan
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andygmac
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Thanks for that Jonathan, your help is really appreciated.
Your fillet looks good :-)
Your 12 inches per min roughly equates to 5mm per second, which is a half mm a second faster than the spec, so it seems to me that we both agree the spec is too slow ;-)
In my final procedure I think I'll up the travel speed as I have to write the final spec myself ;-)
The materials for the fillet is 20mm (3\4")plate for the multi pass and 12mm (3\8") plate for the single pass.
Thanks again for your help Jonathan, you are a hero :-D
andygmac
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You were correct in saying that the vertical leg of my fillet had lack of fusion, I stuck it in the fly press and bust the weld ;-) . I think I need to angle the weld more towards the vertical? I will try tomorrow.
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I don't some more welds with the spec settings, but I couldn't get less than a 8mm (5\16") leg . time to rewrite the spec lol.
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Here is the single pass fillet, bust under the press, I assume this is where the weld should break?
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Cheers for all of your help :-D
Andy
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"IF" it breaks, you want it to break outside the weld.

The goal is that your weld is at least as strong, and preferably stronger, than the parent metal, so your work is not the "weak link" in the equation.

A break between passes (which is what I think I see in your last picture) suggests lack of fusion/lack of penetration.

You need more heat in the weld. Generally, more wire speed gives you more current. If you get too much spatter, increase the voltage a bit, and then bring the wire speed up to match.

Steve S
andygmac
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Cheers Steve. This was only a single pass, the spec was a 6mm (1\4") weld on 12mm (1\2") plate.
I'll have another go today, maybe go to the top settings on the spec and see if that gives me more pen.
Cheers
Andy
andygmac
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OK, so I thought I'd do a side bend on the butt weld, at least it didn't break lol :D
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"LIKE"...

A side-bend pass is a good thing. :D

Steve S
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Your side bend looks great!

After careful review :lol: I am beginning to think the lack of penetration on your T joints is your gun angle. Look carefully back at the pictures you posted. You can see your "nipple" is pointed toward and into your bottom plate. I believe you may be trying to hold a true 45* when you need to actually point a little more toward the vertical plate. I was going to break my piece today and see how it did but we used the other side to set a machine so I will try to get another in soon.

Another thing that concerns me is the last picture has a lot of "balls" laying on the horizontal plate. I am also wondering if either you have way touch push angle or you don't have enough wire and are in fact not at 260 amps. I am leaning toward the gun angle though.

These are just thoughts, let me know what you think.
-Jonathan
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Thanks Steve and Jonathan.
I thought about torch angle too, as the bottom leg is longer than the vertical.
I took all my tests on Monday, cranked up the juice a bit, burnt my knuckles on my left hand through my gloves lol ( Jody needs to invent a tig knuckle lol)
I think I could have done better, but I'm always self critical.
Results will be in next week so fingers crossed.
I'll keep you posted.
Thanks again for all advice,
Cheers Andy
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andygmac wrote:...I think I could have done better, but I'm always self critical...
Cheers Andy
Not the first time I've said it...

We like to call ourselves craftsmen, so we are always our own worst critics.

Steve S
Axis
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Is there a pre-heat on those plates?
andygmac
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Nope, no pre heat, just ambient temperature which was around 28°c in the shop
Andy
Axis
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andygmac wrote:Nope, no pre heat, just ambient temperature which was around 28°c in the shop
Andy
At the school I go to, 12mm (1/2 inch for us barbarians), is about the beginning of the range where we start to pre-heat. Not sure if your spec allows for it or not. Is there a interpass temp you have to maintain?

We also slow cool by burying the parts in a bucket of sand, again, entirely up to spec.
andygmac
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I got the test results back today, passed the procedure test for multi run 20mm fillet, failed on procedure tests for, 12mm single fillet, and 12mm multi run v butt, both failed on "hardness in heat affected area" . so my weld shape, leg length, fusion, penetration, macro, and x-ray were fine, just failed on something that I can't check myself to improve on lol

So, I'm happy in a way that I passed one procedure test, (being the first tests I have ever attempted, and knowing procedure tests are scrutinised more than welder tests)
But gutted that I failed, not on my weld as such, but on the surrounding base metal , grrrrrrr.
Andy
Axis
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Hardness in the HAZ is usually caused by too quick of a cooling cycle, and is extremely common in MIG/GMAW and on thicker material. As I mentioned before, a pre/post heat, and slow as possible post-weld cool down will reduce the possibility of that happening.

Read up on cold cracking and hydrogen diffusion.

Hobart has an easy to understand article on it.
http://www.hobartbrothers.com/index.php ... turnid=523
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andygmac wrote:I got the test results back today, passed the procedure test for multi run 20mm fillet, failed on procedure tests for, 12mm single fillet, and 12mm multi run v butt, both failed on "hardness in heat affected area" . so my weld shape, leg length, fusion, penetration, macro, and x-ray were fine, just failed on something that I can't check myself to improve on lol

So, I'm happy in a way that I passed one procedure test, (being the first tests I have ever attempted, and knowing procedure tests are scrutinised more than welder tests)
But gutted that I failed, not on my weld as such, but on the surrounding base metal , grrrrrrr.
Andy
That's the story of a welder's life. If you meet a man who's never busted a test, you've met a liar.

Steve S
andygmac
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Axis wrote:Hardness in the HAZ is usually caused by too quick of a cooling cycle, and is extremely common in MIG/GMAW and on thicker material. As I mentioned before, a pre/post heat, and slow as possible post-weld cool down will reduce the possibility of that happening.

Read up on cold cracking and hydrogen diffusion.

Hobart has an easy to understand article on it.
http://www.hobartbrothers.com/index.php ... turnid=523
Cheers for that :-)

Pre and post heat would be an option but we are trying to avoid this because if any heat is used in the procedure test, then it would have to be used in every weld thereafter which in our production would cost time and money lol

The strange thing with my fails were that they were both on the 12mm plate, one v butt multi pass (7passes), and one single pass fillet. The passed test was 20mm plate multi pass fillet. It was hot on the test day with the workshop having an ambient temp of around 30°c. All test pieces were allowed to cool on the bench, no quick cooling.
There were no cracks found in any of the welds, they were x rayed, mpi, cut, bent, etched, impact tested, and inspected under a microscope, and the fail was hardness in the haz.

A good workman always blames something else, so I'm blaming the 12mm plate ;-) he he he

You are right Steve my motto is " he who has never made a mistake, has never made anything" ;-)
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andygmac wrote:
Axis wrote:Hardness in the HAZ is usually caused by too quick of a cooling cycle, and is extremely common in MIG/GMAW and on thicker material. As I mentioned before, a pre/post heat, and slow as possible post-weld cool down will reduce the possibility of that happening.

Read up on cold cracking and hydrogen diffusion.

Hobart has an easy to understand article on it.
http://www.hobartbrothers.com/index.php ... turnid=523
Cheers for that :-)

Pre and post heat would be an option but we are trying to avoid this because if any heat is used in the procedure test, then it would have to be used in every weld thereafter which in our production would cost time and money lol

The strange thing with my fails were that they were both on the 12mm plate, one v butt multi pass (7passes), and one single pass fillet. The passed test was 20mm plate multi pass fillet. It was hot on the test day with the workshop having an ambient temp of around 30°c. All test pieces were allowed to cool on the bench, no quick cooling.
There were no cracks found in any of the welds, they were x rayed, mpi, cut, bent, etched, impact tested, and inspected under a microscope, and the fail was hardness in the haz.

A good workman always blames something else, so I'm blaming the 12mm plate ;-) he he he

You are right Steve my motto is " he who has never made a mistake, has never made anything" ;-)
First thought, you can put the test piece in a bucket is sand or wrap in fiberglass, this will allow for a slow cool and you might be able to get away with this. However, it is best to figure out why this is happpening and how to fix it. I would hate for you to have problems in the future.
Ok now define "hardness in the HAZ". What was acceptable and where did you fall? I will try to get a friend to help out with this one, hopefully.

Steve,
Took the words right out of my mouth!!
-Jonathan
andygmac
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Cheers Jonathan, I'm waiting for the paperwork to come back to me, the test lab is real busy at the moment so they just emailed my results to me, with the paperwork to follow, hopefully this will give me more of an idea what went wrong, I'm still blaming the 12mm plate lol
Cheers Andy
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