[MW:13860] Re: SAW WELDING-POROSITY

Dear Raj

You can take a note of the followings

1. Clean the connector bevel surface prior to its fitment on the pipe (remove traces of grease, generally applied on the threads of connector). Better apply emery disk to remove phosphating on connector bevel.

2. Clean the weld groove after fitment (fitment of pipe end to connector) by pneumatically operated wire brush system after heating the joint up to 120 Deg C (to remove traces of grease)

3. Again clean the joint after GMAW welding (before preheat & SAW) to get a shiny surface in and around weld groove.

Above will improve the weld soundness.

You can also try Lincoln 995N flux to get better results, however clean weld groove is the key.

Regards

Punit Dubey

On Tuesday, March 6, 2012 3:49:49 PM UTC+5:30, raj susi wrote:

Dear Experts   I m working with a Casing Connector Joints and the details are as follows:-   20" x .625" X80 pipe - 4130 Q & T Box and Pin Connectors; WPS qualified is with GMAW and SAW;   Preheat Temp 400F, Int Pass Temp 600F.   ROOT PASS - GMAW - ER 100 SG wire,Gas 75% Argon & 25% CO2, 30-50 CFH;   ID Backing and OD passes - SAW(DCEP) - Lincoln LA 100 wire(F10A6 EM2 M2 H2), Flux-Lincoln mil 800H, 5/64 wire thk - Amps - 280-350, Volts - 28-31, Travel speed ipm-17-25, & 3/32 wire thk - Amps - 350-470, Volts 28-31.5, Travel speed 25-30.   Although all the consumables are in good conditions In X ray Film we can see some porosity's here and there. But this porosity is not from the GMAW PASS, and these porosities are not visible to eyes ie they are not on the surface and suspected to be in side the weldment..   Is there any other cause for the porosity's ie other than Clean Surface preparation, Wet(moist) flux, Rusty filler Wire etc.   I m unable to control this porosity, So I need all your valuable advise for this case.   Thanks and regards raj

On Tuesday, March 6, 2012 3:49:49 PM UTC+5:30, raj susi wrote:

Dear Experts   I m working with a Casing Connector Joints and the details are as follows:-   20" x .625" X80 pipe - 4130 Q & T Box and Pin Connectors; WPS qualified is with GMAW and SAW;   Preheat Temp 400F, Int Pass Temp 600F.   ROOT PASS - GMAW - ER 100 SG wire,Gas 75% Argon & 25% CO2, 30-50 CFH;   ID Backing and OD passes - SAW(DCEP) - Lincoln LA 100 wire(F10A6 EM2 M2 H2), Flux-Lincoln mil 800H, 5/64 wire thk - Amps - 280-350, Volts - 28-31, Travel speed ipm-17-25, & 3/32 wire thk - Amps - 350-470, Volts 28-31.5, Travel speed 25-30.   Although all the consumables are in good conditions In X ray Film we can see some porosity's here and there. But this porosity is not from the GMAW PASS, and these porosities are not visible to eyes ie they are not on the surface and suspected to be in side the weldment..   Is there any other cause for the porosity's ie other than Clean Surface preparation, Wet(moist) flux, Rusty filler Wire etc.   I m unable to control this porosity, So I need all your valuable advise for this case.   Thanks and regards raj

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