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stainless weld test
Posted: Sat Oct 05, 2013 12:15 am
by Jason123177
Recently I busted a 2" sch 80 6g welded with 309 stick. It was supposed to have a backing ring, but they were out of them, so I just butted it up. I was using 3/32 rods and running about 80-85 amps. I took a similar test a few years back and passed it with flying colors. I just can't for the life of me remember what amperage I was running on that one. All of my cap passes came out humped up in the middle and it dripped out on me a few times which after thinking about it leads me to believe that my amps were too high and I didn't let the coupon cool enough between passes. Any tips or suggestions for next time I have to take this sort of test?
Re: stainless weld test
Posted: Sat Oct 05, 2013 9:26 am
by rake
Piss a lot! LOL! What I mean is that a test is a test, not a race!
Especially with stainless. Stainless doesn't really like heat and
will only tolerate so much. Let it cool between passes. You work
your jake off trying to get a proper root pass in only to grape it
out and blow through it on the hot pass. That's an automatic failure.
Just wire brush the hell out of it between passes to kill time. Piss and
water breaks too if it's allowed. Remember, coupons heat up fast cuz there isn't a lot
of mass to suck up that heat input. wait till you can touch it bare handed
between passes before starting a new pass. There are no extra points for speed.
Re: stainless weld test
Posted: Sat Oct 05, 2013 9:31 am
by Jason123177
Pretty much what I thought. Do you think 85 amps are too much for 3/32 309L on 2" sched 80?
Re: stainless weld test
Posted: Sat Oct 05, 2013 9:40 am
by rake
Normally that should be okay but machines are not calibrated. If it feels hot and you have
trouble keeping the puddle satisfied then turn it down. I took a 3G test on carbon once and
the machine was so hot I was running 1/8 8018 with the machine set at 75 amps! And it still
was a tad hot!
Re: stainless weld test
Posted: Sat Oct 05, 2013 11:36 am
by jwmacawful
Jason123177 wrote:Recently I busted a 2" sch 80 6g welded with 309 stick. It was supposed to have a backing ring, but they were out of them, so I just butted it up. I was using 3/32 rods and running about 80-85 amps. I took a similar test a few years back and passed it with flying colors. I just can't for the life of me remember what amperage I was running on that one. All of my cap passes came out humped up in the middle and it dripped out on me a few times which after thinking about it leads me to believe that my amps were too high and I didn't let the coupon cool enough between passes. Any tips or suggestions for next time I have to take this sort of test?
sorry you busted out but how can anyone take and pass a test if the joint spec calls for a chill ring and they plumb ran out but had you take it anyway???
Re: stainless weld test
Posted: Sat Oct 05, 2013 1:18 pm
by Oddjob83
well here in Canada, we do have a time limit, 45 min and even for our regular mild steel tests about 30-40 mins was normal. can you use compressed air to cool it off or a fan? or move the fume extractor right up to it so it sucks the air through the pipe?
Re: stainless weld test
Posted: Sat Oct 05, 2013 4:56 pm
by Jason123177
jwmacawful wrote:
sorry you busted out but how can anyone take and pass a test if the joint spec calls for a chill ring and they plumb ran out but had you take it anyway???[/quote]
Not having the chill ring wasn't a big deal. I thought it was going to be though. I just butted the coupons up and ran the first pass like a hot pass. Busting it didn't really hurt my feelings because it was for a crappy job doing tower work in plants.
Oddjob83 wrote:well here in Canada, we do have a time limit, 45 min and even for our regular mild steel tests about 30-40 mins was normal. can you use compressed air to cool it off or a fan? or move the fume extractor right up to it so it sucks the air through the pipe?
There was no time limit, but I finished it in about 40 minutes even with the trouble I was having. I think I just rushed it and there was no way to cool it off faster.
Re: stainless weld test
Posted: Mon Oct 07, 2013 1:42 am
by Vince51
I like 75 amps. They do ok up to 85 or so. After that the flux just can't stand the heat. Anytime I take a stainless test a spray bottle of water will be nearby. Should be able to touch the coupon. If you can't just give it a spray.
You can put a decent root pass in with them, but you'll have to be patient. When it starts to keyhole just bring the arc out on the bevel a little until it closes up. It's very easy to trap slag in the root pass with stainless stick. When you restart on your cap do it right on the crater. Don't strike and drag back, or you'll have a pinhole. You can't distinguish the puddle like 7018 so steady travel speeds will help you alot. Good luck with it.
Vince