There are several manufacturers of straight length, cut, flux cored filler metal (Kobelco being one) specifically designed for use with GTAW. These were designed for root welding when an inert gas purge could not be performed. Typically the flux cored filler metal is used for the root pass only (as use in subsequent passes leads to weld defects such as entrapped slag, lof, etc). This is NOT FCAW it is simply GTAW with a specialized filler metal. This is provided for in ASME Section IX QW-256, Welding Variables Procedure Specifications GTAW, by essential variable QW-404.23 which requires identifying whether the filler metal is solid or metal cored, flux cored, or powder.
This type of filler metal has been used to weld superheat tubes in fossil fuel power plants with great success.
John
-----Original Message-----
From: materials-welding@googlegroups.com [mailto:materials-welding@googlegroups.com] On Behalf Of israr
Sent: Saturday, October 03, 2009 4:36 AM
To: Materials & Welding
Subject: [MW:3409] Re: application of SS Flux cored wire for GTAW, SFA 5.22
Dear Mr Raghuram,
I don't understand GTAW with Flux cord wire, it should be FCAW.
My suggestion is to do it with gas purging for better penetration and fast production.
Or Use SMAW process because i have qualified so many welders in SMAW with better penetration. or use combine process SMAW for Root and Hot Pass Filling and Capping with FCAW.
On Oct 2, 5:24 am, ikaria73 <ikari...@hotmail.com> wrote:
> JZ,
> You are correct. If proper training is not conducted with the STT
> process, the type of defects you experienced will be common. Lincoln
> developed STT in the late 1980s and has been a proven process on in-
> house and cross-country pipe but proper training is important.
> Fortunately most of Lincoln's technical sales representatives
> graduated from college as engineers and have been trained to properly
> weld with STT. Hopefully they can help.
>
> Regards
>
> On Sep 25, 3:08 pm, Jeremy Zibin <jzi...@yahoo.com> wrote:
>
>
>
> > Something to add to this GMAW discussion:
> >
> > I've performed quality control work and inspection at a large piping
> > fabrication shop where they were using mainly STT GMAW because of the high production rates inherant with this welding process. There were mainy issues with lack of fusion or porosity in the root and the quality of welds being of concern. I've later talked with welding engineers and consultants who have said that any type of GMAW process, whether its STT or other, will be susceptible to these types of defects, especially in the root of the weld.
> >
> > I'm not saying it's impossible to perform but the welders must have very good training with the capabilities of the machines and they must be aware of the difficulties in root welding otherwise you will have a large quality "headache" on your hands. One possible solution is to grind away any weld starts that are suspect at having defects before welding over with the following passes (the welders at the shop I was working did not do this from what I could see and hence, likely propagated the problem).
> >
> > Regards,
> >
> > J.Z.
> > Materials & Welding Engineer
>
> > --- On Thu, 9/24/09, Vishal Mehta <v...@supertechservices.in> wrote:
>
> > From: Vishal Mehta <v...@supertechservices.in>
> > Subject: [MW:3309] Re: application of SS Flux cored wire for GTAW,
> > SFA 5.22
> > To: materials-welding@googlegroups.com
> > Received: Thursday, September 24, 2009, 9:24 PM
>
> > Yes, STT is a good option only if you could use GMAW process. And its worth an investment only if such jobs are regular.
>
> > Besides STT, even Miller Electric has developed their patented
> > technology RMD - Regulated Metal Deposition. Machine Model is
> > Pipepro 450. Its somewhat similar to STT and a little more to offer.
> > checkwww.millerwelds.com
>
> > Regards
>
> > VISHAL
>
> > On Fri, Sep 25, 2009 at 8:54 AM, vipin george <vipingeor...@gmail.com> wrote:
>
> > Dear Bathula,
> >
> > A new process is developed by Lincoln STT(Surface tension transfer) it's GMAW process with short circuit transfer.It's good for piping applications.Check Lincol electric.
>
> > Regards,
> > vipin
>
> > On Tue, Sep 22, 2009 at 12:57 PM, Bathula Raghuram (Mumbai - PIPING) <R.Bath...@ticb.com> wrote:
>
> > Dear members
> > We have typical vessel (site assembly), where backing gas arrangement could not be done for a stainless steel joint due to Safety (confined space), as well as space constraint.
> > One of the options will be using flux cored wire for GTAW.
> > Please share your view on these consumables for root pass of GTAW Stainless steel; where backing gas application is impractical, any body used these consumables?
> > Kobleco is manufacturing these wires under TGX series, any other manufactures who has similar product for this application?
>
> > --
> > SUPERTECH SERVICES LTD
> > Plot A-253, Road 30B,
> > Wagle Indl Estate,
> > Thane W 400 604
> > Maharashtra, India
> > Tel: +91-22-25826190/91
> > Fax: +91-22-25826189
> > Email: v...@supertechservices.in
> > Web:www.supertechservices.in
>
> >
> > __________________________________________________________________
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> - Show quoted text -
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