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Tig t joint nickel base alloy

Posted: Thu Mar 16, 2017 10:33 pm
by KLRX650
IMG_3277.JPG
IMG_3277.JPG (64.38 KiB) Viewed 494 times
I am having trouble with a pin hole size .010 on a certification test
Machine is Dynisty 350 base metal nickel alloy .093 -.093 t joint filler rod 718 ni in a fixture with long electrode stick out I have ran the joint 4 times same results pin hole in the root need help anything would help

Re: Tig t joint nickel base alloy

Posted: Sat Mar 18, 2017 9:15 am
by dirtmidget33
Bead looks very wide with another pass over it. Second pass looks like a wash to attempt to smooth out weld. as wide as the bead looks would say arc length is way too long spreading out arc so your not able to focus arc in root. This also causes voltage to increase and puts excessive heat into part. Keep a very tight arc length and focus arc in root. One pass on .093 should be more then sufficient. Plus maintain good torch angle. Looks like excessive filler causing distortion along with excessive heat causing distortion too.

Grabbed this off web for you
weld-fusion5.jpg
weld-fusion5.jpg (15.6 KiB) Viewed 463 times
Pic is from lincoln web
http://www.lincolnelectric.com/en-us/su ... gle.com%2F
jk66f4.gif
jk66f4.gif (16.58 KiB) Viewed 466 times
Pic taken from http://www.twi-global.com/technical-kno ... ities-066/

Re: Tig t joint nickel base alloy

Posted: Sat Mar 18, 2017 9:57 am
by LtBadd
dirtmidget33 wrote:Bead looks very wide with another pass over it. Second pass looks like a wash to attempt to smooth out weld. as wide as the bead looks would say arc length is way too long spreading out arc so your not able to focus arc in root. This also causes voltage to increase and puts excessive heat into part. Keep a very tight arc length and focus arc in root. One pass on .093 should be more then sufficient. Plus maintain good torch angle. Looks like excessive filler causing distortion along with excessive heat causing distortion too.
Good advice, make sure base material and filler are clean, keep the filler in the argon shield between dips.