E71T-1M in cjp

Date 03-14-2011 23:53

I am thinking of using 1/16" E71T-1M in 1/2" joints (B-U6-GF). We would use a backing weld and I intend to weld a few samples (etched after welding) to find the best voltage and wire feed speeds for the most penetration without getting too hot for the man doing the welding while staying within the manufacturer's recommendations. On the 'U groove" side of the joint I will weld a few samples to find the optimum pass / bead size for fewest number of passes with no inclusions. I realize much of the outcome I am looking for is dependent upon technique. I am hoping to cut down on some of the time spent on this by asking if anyone has any suggestions on where I might start with the voltage and wire feed speed. Any other suggestions based on experience with the E71T-1M would be greatly appreciated.

By Lawrence (*****)

Date 03-15-2011 01:02

I have used 1/16 Hobart, Lincoln, ESAB and Corex E71T-1M electrodes and have found that the manufacturers ranges for position are right on the money for both WFS and Voltage. I've never run more than a volt above what is published.

So if you are buying a known brand of electrode you will prolly do best to access their data direct... I *really* doubt you will have any difficulty if you do this.

By 625552

Date 03-15-2011 03:30 Edited 03-15-2011 03:34

Thanks. I had a guy start with some samples, I inspected the groove side after backgouging and it looked fine but was unable to witness the welding of the groove. When I cut them the majority of them had an inclusion or two in them. I figure he tried to weld the joint with too few passes because this guy doesn't like to push his welds or do any weaving. We'll try again tomorrow with smaller passes, any recommendation on bead / pass size on the groove side of the joint?

By Lawrence (*****)

Date 03-15-2011 04:06

Really depends on whats going to be used in production.

FCAW should be dragged for *everything* but vertical-up welds. I've been teaching this way for 8 years and while we have some fusion issues at the root/backing strip from time to time.. I have never seen a slag inclusion in a FCAW test weldment done with a drag.

Weaves (the allowence of) depend on any heat input regulation that may be in place. Weaves are fine in everything but the horizontal positions, but stringers tend to trap less slag.

The wire you are talking about will easily do 5/16 single pass fillets, prolly 3/8 would be a snap.

If the prep and backing weld are kosher, you should see absolutly no slag inclusions.

By 625552

Date 03-15-2011 12:50

Thanks.