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Up Topic Welding Industry / Inspection & Qualification / charpy impacts thickness across the notch.
- By Mikeqc1 (****) Date 11-18-2010 16:46 Edited 11-18-2010 17:56
On charpy impacts, where the MTR notes size (.394 x .295) is there a standard as to which dimension represents the Thickness across the Notch. I would think that the .295 would represent thickness across the notch…… any 1 agree or disagree.
see mtr 5" sch 80 sa333 gr6
its become a diagreement should this temp for impact test be reduced?
MDK
Attachment: _1118125146_001.pdf (766k)
- - By Mikeqc1 (****) Date 11-18-2010 21:16
in another case same manufaturer....how can i have a impact size of .394x.295.....with a pipe  actual wall thickness of .281?
Im not comfortable with this.
any advise experiance?
MDK
Parent - - By js55 (*****) Date 11-19-2010 13:33
If I understand the question correctly, for pipe if you reduce the thickness it is the thickness longitudinal to the notch that is reduced since the notch must be perpendicular to the surface of the pipe. As the pipe wall gets thinner the length of the notch would naturally get shorter as well.
Parent - - By Mikeqc1 (****) Date 11-19-2010 13:57
do you think in the first post the test temp should have been reduced?
Parent - - By js55 (*****) Date 11-19-2010 16:15 Edited 11-19-2010 16:19
By 3deg C.
But this brings up an interesting reality. Unless they have thermocouples on the specimen at the notch, which they don't, you cannot determine 3deg C. You can't determine 10deg C. By the time the thing is pulled out of the bath set up on the anvil and smacked with the hammer what temp is it?
Who the hell knows.
Its an estimate anyways.
Parent - - By Mikeqc1 (****) Date 11-19-2010 16:39
but the temp recorded was wrong.............so    nfg.
Parent - - By js55 (*****) Date 11-19-2010 17:34
Oh I agree. The right number has to be on the MTR or its a reject.
Parent - By Mikeqc1 (****) Date 11-19-2010 21:03
I have been given 3 different reasons why the sample is acceptable, but i have shot them all down. the only thing i can think is what if the sample sent was at the low end of the wall thickness tolerance, or do i use the nominal wall thickness?
Parent - By Mikeqc1 (****) Date 11-24-2010 00:58
in the above MTR for tensile tests could any1 tell me what the orientation is to get those dimensions from a pipe with a wall .375.
Parent - By Mikeqc1 (****) Date 11-19-2010 22:55
Well i guess im going to Have the pipe retested.
Parent - By Mikeqc1 (****) Date 11-19-2010 14:27
right thats how i see it.
Up Topic Welding Industry / Inspection & Qualification / charpy impacts thickness across the notch.

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