Welding Tips and Tricks

Can someone give me some advice, i have to do a stainless steel pipe 50mm x 4mm in the hv position with tig, what root gap and root face (if any) do i use, also what filler wire 1.6 or 2.4. I will be using a pulsed tig set so what amperage and frequency should i be on for the root, any help would be appreciated thanx.

Hey,

welcome to the forum. We've got plenty of advice but how about dropping by the Members Introduction area and introducing yourself first.

Mick

Hey,

Have you been checking out Jodys' tig videos? He has a lot of pulse videos, also our othe moderator , Otto, lays ALOT of stainless tig. I dont do alot of production tig, mainly repair, im sure another member will help you lock it down.

Mick

Hi, Andy,

I've been all over the map with the specifications you've asked about, so I'll try to give some more general suggestions. I have to equate the dimensions you've given to SAE (read hard-headed Americans) standards.

50mm equates to 2" tubing here, and the 4mm wall is almost exactly 5/32".

I'm going to assume the "hv" position (horizontal/vertical?) equates to our 6g test, meaning the pipe is inclined and fixed at 45*. I'm also going to assume an Austinitic alloy such as 304 or 316, and therefore 308 or 316 filler.

There is a difference between "certifying" and "qualifying", and you should know which they need you to do. "Certifying" means demonstrating your welding ability to a specific weldng code, and the parameters you can work within will be spelled out in a detailed WPS (welding process specification). "Qualifiying" means testing to the customer's requirements, which should also be spelled out, at least generally, even if they are not code-specific.

Given my choice for the test you are taking (ignoring any possible requirements), I like to use a 37* bevel both pieces, 1.6mm gap, 0.8mm land, with 1.6mm rod for the root pass. Unless you are experienced with pulsed TIG, I'd leave this feature off. Just 'cause you can doesn't mean you should. I'd keep an average current of around 60A for the root, so I can take my time. (If you ARE experienced with pulse, I like 1 Hz, 40% background, 50% peak time, peak at 70A, and that's a very personal preference.)

For fill and cap, I'd move up to 75-85A, wherever you're comfortable, and 2.4mm filler.

I hope they give you practice time, since this seems to have come from out of the blue!

I'm sure others will chime in with other suggestions (I've never known two who do it the same way), to help you find a starting point you're comfortable with.

Let us know how it goes?

Steve S

Hi steve, i go back to work tomoz and yes it has come out of the blue but at least i will have time to practice as the qualification guy is coming next week.
i have been using pulsed tig on stainless doing fillet welds and branch welds they are coming out fine, but never done a 6g in stainless before so the info you have kindly provided for me is great, also for this one think i will leave the pulse off as i am not confident enough using it at the moment.
Thanx again for the info you have been very helpfull and will let you know how it goes (fingers crossed).

Andy.

Good luck, Andy,

And, I'll add, it's hard not to be self-concious during a test. It makes you hyper-aware, and that's not a good thing. Just do what you know, try to pretend it's just practice, and don't drink too much coffee (or tea, as the case may be)!

Steve S