stringers vs weave testing

  1. gaz1

    gaz1 Forum Supporter

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    i found this while been nosey

     
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  2. Rrunnach

    Rrunnach www.interventiontechnolog y.com

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    What a blast from the past, run on, run off, plates.........................always been stringers all the way!
     
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  3. premmington

    premmington Member

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    +1 for stringers
     
  4. +2
     
  5. TechnicAl

    TechnicAl Member

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    If it was only that simple......the "weave" tensile had "fish-eyes" which only emerge under stress....you cant see them on X-Ray but its Hydrogen....the test piece should be subjected to a hydrogen release treatment (250 oC for 12 hours)....they go blue so thats another sign they werent treated.

    Its really all about recrystallisation of the grains.....therefore by putting a big cap on you can cut the Charpy from almost all "as welded" weld metal.....cut it a bit lower, so that it contains more recrystallised weld metal and the results would be better.
    On say 20mm plate if you run thin beads, you will probably get better results from say a split layer than a layer of 3 or more stringers. I used to keep layer thickness to less than 4mm and keep the heat input above 1.5Kj/mm (which means a weave) and interpass of 180 oC.
    |That would give the best CVN results and hopefully the tensile would hold up....If it doesnt Id allow it to cool a bit more (interpass temp).

    You can affect the results by quite an amount by messing around with these parameters....enough to make the difference between passing and failing

    One big job we were involved in reported back that all their Tensiles had failed and I had to go straight away.....I could see the test pieces werent blue so they hadnt had the hydrogen release..
    We sat them on a radiator overnight
    They all passed next day...that was the only difference
     
  6. TechnicAl

    TechnicAl Member

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  7. slim_boy_fat

    slim_boy_fat Forum Supporter

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