Long time reader first time poster

By fabricator19 Date 08-27-2008 13:54

Hi everyone, names Rob im from allentown pennsylvania... Been reading the forum for a little while now. Couple days ago i took my first cert tests they were ASME section 9 codes for air products... I passes the 2G FCAW with flying colors it was a three part test the other two were 2G and 3G SMAW 3/8'' plate with backin strip using E7018. Now i failed those two test for lack of fusion... not exactly sure where in the test but most likely at the root. my heat range for the 2g was about 125 amps. for my 3g it was slightly cooler running around 110amp... was wondering what i could do different because i re-test friday at 9am they really want me and are willing to give me a second chance dont wanna blow it this time... i know all welders bust test one time or another but im tring to learn from my mistake this is a really good job for the area and would really like to work with these peoples... Any advice would be helpfull thanks alot

-Rob

By medicinehawk01 (**)

Date 08-27-2008 22:46

Hi Rob,
Sorry to here about the re-test thing, but it is cool they will let you take it again. Did you bust both the 3G & 2G (using backing strips) welding with 7018 all the way??? Remind what positions those are because I have forgotten. 2G = plate/joint horizontal? 3G= plate/joint vertical? Anyway, regardless of the position, you probably had lack of fusion which means when the bent the specimins.....they cracked on the root side. Really could have been the face side too, but you'll need to find out those details. Really hard to say what happened, but I know this.......IF you cracked a root bend, it is probably because you had slag inclusions or you long arc the root pass. Generally speaking, it is hard to crack 7018 unless you had too much heat or moved too slow or long arced the whole thing. Again, need more information. Try to run a bit cooler on the vertical pass, say 90-100 amps and paying extreme detail to your arc length. Give us some more details and then we can do the same.
Be well,

Hawk

By jwright650 (*****)

Date 09-02-2008 19:49

When I had someone who simply did not get good penetration and lack of fusion at the root or against the backing bar...they were trying to carry too much of a puddle and the puddle ran ahead of them too far. You didn't mention what size E7018 you were testing with, but from the amperages you mentioned I would venture to guess 1/8". That will work for the 2G Horizontal test, but is a bit too hot for me to handle on the 3G Vert UP test, I like to turn it down to about where hawk mentioned(90-100). You didn't mention how you were running the Vert UP test...stringers or weave?