two welding PQR procedure( SAME GROUP) can add thickness

[stan000]

friends
i would like to weld 1" P10H
I do have two different procedures PQR of 3/8" plate qualified 3/4" , both only gas is different
ONE HAS ( AR,HE,CO2) & OTHER ( AR,HE,CO2 & N2 )
can i used two different procedures to weld 1" plate.
please advice.
stan

 

No. PQRs are not additive in terms of base metal thickness.

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

 

[stan000]

I WAS THINKING, IF IT IS DOUBLE V GROOVE, THEN I WILL USE FIRST WPS PROCEDURE TO WELD 1/2"& THEN USE OTHER WELDING PROCEDURE FOR OTHER HALF 1/2"
SO I DO NOT HAVE TO MAKE SEPARATELY WELDING PROCEDURE FOR 1".
PLEASE ADVICE

 

[r6155]

Not allowed.
You must include two different procedures in the same test plate.
See ASME IX.

Regards
r6155

 

I am a career welding engineer and I find duplex SS problematic.
You are clearly new to welding, never mind welding of more difficult materials.
I strongly suggest you bring in a consultant WE who has experience with the intricacies of P10H.

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

 

[weldstan]

You need to make an additional PQR on 1/2" material, minimum to permit welding on 1" thick material. Agree with ironic metallurgist. I foresee some real problems for you and the welds made in 1" thick duplex ss. I suggest that you obtain literature from Avesta and Outokumpu on this subject and read it closely.

 

[sharmass]

Dear Stan3126
Both base metal thickness and deposited weld metal thickness are two different essential variables. PQR made on 3/8" thick is qualifying minimum 1/16" and maximum 3/4" base metal and a maximum of 3/4" weld metal thickness. You can't use any of your PQRs to weld a 1" thick base metal.

 

[pradipgoswami]

Hi Stan000,
A separate PQR is required to qualify welding procedures to weld up to 1" thick.Frst of all the combinations of the qulaifed PQR's do not add uo to weld 1" thick base metal. Also the shielding gases are different warranting a new PQR to be qualified, refer QW 408(C).
To come back to the point of Duplex welding:
[ul]
[li][/li]
[/ul]It requires a careful and through evaluation and planning prior to welding of any procedure or production welds.

Pleanty of resoureces are available as guidence for welding DSS, however thourough understanding of metalliurgy and welding processes are required to get the due success.

Thanks.



Pradip Goswami,P.Eng.IWE
Welding & Metallurgical Specialist
Ontario,Canada.
ca.linkedin.com/pub/pradip-goswami/5/985/299