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ARCDAWGS TIG pic's

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  • gregj66
    replied
    Got it now.

    The test wasn't designed to stress the joint at the same load as the metal tube should capable of handling. I thought that if the tubing should be able to withstand X amount of load, then the test would apply that load to check the weld. Does that make sense?

    If it is destructive testing, then of course it should be destroyed or the test itself failed

    I have also seen a lot of "blob" welds on the equipment we use at work, but I have noticed that there is always a strong physical joint thereby minimizing the load on the weld itself.

    Thanks for the info guys

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  • Paul Seaman
    replied
    Dawg:
    Most of the dirt track guys blob it together and if it holds great if not they do it again. Most of us here wouldn't trust alot of what is seen under a car at the local dirt track. The sanctioning bodies police what they can but these cars are in frequent colisions and most intend well but they just don't know what HAZ is or how it will affect the race car in a solid contact with an nonmovable object {wall}.

    Peace,

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  • arcdawg
    replied
    Originally posted by gregj66
    Arcdawg I like your weld and I would be very happy laying such a fine bead. But, I am a newbie and when I saw the break along the HAZ I needed to know for my own education if that was normal.

    I understand that the weld did not break (fail), but the "joint" did. The victim isn't going to give a rat's bum where the joint failed, but only that it did in the first place.

    Greg

    it has to deal with post heating the joint we had a guy in the class that ran a really nice bead on the c.m. and threw it in water to cool it and well.......

    like i have stated previously in this thread..... i did what i was told to do and it took a few trys and i got it (passed the test)

    and as far as someone giving a rats bum........ next time you go to a race ..... take a look at the welds..... i can assure you that you wouldnt wanna take it around the track

    Leave a comment:


  • Ryphraph
    replied
    I think Fun4now hit the nail on the head. This was a "destructive test". It is going to fail somewhere. The point of the test was to produce a joint which would not be the point of failure. If the HAZ is what caused the break I think it would have happened a bit closer to the bead.

    Ryph

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  • fun4now
    replied
    gregj66

    I understand that the weld did not break (fail), but the "joint" did. The victim isn't going to give a rat's bum where the joint failed, but only that it did in the first place.

    just because the pipe broke dosent mean there would be a victim.
    manny tests are setup to far exceed the limitations of the aplication. as was stated earlyer we dont know the amount of stress aplied to this joint . if it were a child's tricycle and the test aplied 50,000 lbs of force befor breaking i think the child would be safe. as i understand it manny tests are setup to see how much it will take befor somthing breaks, somthing will always break. it is the amount of force that it takes to make it break.supose the pipe unwelded would withstand 50,000 lbs if it were never welded on and this pipe broke at 49,950 lbs would you call it a bad weld then. or would you say even the pipe makeing process could have caused the 50lbs early break. everything has a + or - of some sort.
    every thing will break thats why they call it a destuctive test.

    without exact numbers of the test we can only say it look's like a fine weld

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  • arcdawg
    replied
    from what i was taught you want a equal amount on each side of the weld...... you get into pre and post heating to control the metaluracal properites of the base metal......

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  • DEA
    replied
    So how do you cure this problem in the HAZ area?Travel faster,lower amps??
    How much is to much HAZ area?
    Thanks
    Doug

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  • gregj66
    replied
    Arcdawg I like your weld and I would be very happy laying such a fine bead. But, I am a newbie and when I saw the break along the HAZ I needed to know for my own education if that was normal.

    I understand that the weld did not break (fail), but the "joint" did. The victim isn't going to give a rat's bum where the joint failed, but only that it did in the first place.

    Greg

    Leave a comment:


  • arcdawg
    replied
    i posted these pics for feedback and like i had posted earlier to show my skill level..... one of the first things that i learned about being a welder (good one) was to be able to be critequed and if i felt that my welds were a little ifffy i would not have posted them..... so everyones imput is a GOOD THING....

    and i am not easily offended ( i used to bartend )

    now getting back to the c.m. i did exactly what i was told to do by my instructor (this weld being done in school) what i was told was to notch the c.m. clean it tack it clean it again then run some er-70 tig filler at around 70 amps give or take....... the first one i did was to hot and when bent under the 5000psi it broke right down the center of the weld (so it FAILED)

    this one broke outside the weld so it PASSED..... i have NO reason to tell anyone that it passed if it didnt.....

    dawg

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  • paulrbrown
    replied
    dyn88. Carbide Percipitation is only visable with a Microscope on a polished & etched specimen. what you are refering to is probaly known as 'sugar' and is caused by atmospheric contamination due to no shielding gas in that area, kinda like weding with no gas at all, but only affectiong the rear...this is one of the reasons for not using xx18 rods on a SMAW open grovve weld, there is very little gas coverage as the heavy slag acts as the main atmospheric barrier. Hope this helps, Paul

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  • HAWK
    replied
    dyn88,

    Good point. As for promising skill he has it!

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  • dyn88
    replied
    I dont think a backup would reduce the haz, but it possibly could reduce the carbon precipitation(I think may be using term incorrectly but you will let me know ffrom context) on the inside of the pipe and preventing surface hardening of the haz on the interior of the pipe. The reason for the tear is the difference in ductillity present in the two areas. Ive never backed up CM. My earlier post was mainly to let dawg that he definately showed some skill and that although many armchair quarterbacks are quick to draw conclusions, there are those of us who will offer an opinion without critisizing. Im not being mean just conveying my thoughts.Sorry in advance to all those who may be offended.

    Leave a comment:


  • HAWK
    replied
    dyn88,

    It is hard to tell from the pics, but it looks like there was no backing shield. Do you think a non-reactive gas purge would decrease the HAZ given the same weld parameter? I do agree a faster travel rate will effectively reduce the heat input and shrink the HAZ. If this were SS I would definitely use a gas dam or similar backing. I don't think it is absolutely necessary with CM. Thoughts???

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  • dyn88
    replied
    jeez dawg you cant catch a break. There are several unknown contitions here. Where were the stresses applied during the test? Where is the seem in the pipe? How old was the pipe, or corroded? was this joint backed up with gas? Is the material pipe or tube(the two are different in size and wall thickness also in manufacture). the weld looks good, but did you use a lens? try traveling faster with same heat and retest. Its amazing how fast some people jump to conclusions without the full knowledge of the product. Just do it is the famous saying of failing supervisors and only shows.

    Leave a comment:


  • KB Fabrications
    replied
    Dawg,
    I hope I have not offended you. I never said YOUR weld was bad. I did describe a situation where "I" would consider a weld to be bad. That being said, I don't know the parameters of your test or what the instructors were looking for. I do know that the three companies that I contract for would consider that weld unacceptable.

    I do think your welding shows promise and look forward to seeing more of your pictures. Again sorry if I offended.

    Leave a comment:

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