Re: [MW:5525] FW: Urgent quarry on filler wire selection and heat treatment after welding

Dear Das,

 

Please understand that PQR is conducting to evaluate the mechanical proprerty of the welded joint you are going to do in production welding.

 

The equipment will subject to following physical loading at operation mainly :

 

1) Internal  & External pressure at elevated or lower temperature

3) Impact loading at low temperature

 

So before doing the welding of the job you have to prove that the weld is sound enough to withstand the loading.

It is proving by welding a test coupon with the matching consumable having minimum tensile strength, low temperature toughness ,

corrosion property, hardness etc...

 

To reduce the number of PQR, ASME Sec.IX has listed the base material to different P numbers and filler metal to F numbers and A numbers. And also provided some essential variables, supplementary variables and non essential variables.

 

If your PQR does not meet the essential variables you have to qualify a new PQR.

eg 1: Your PQR is qualified with P1 material and your equipment is P4 material. You cannot use this PQR for this welding as P number is an essential variable.

 

eg 2: Your PQR qualified without PWHT and the equipment require PWHT then you have to qualify a new PQR as PWHT is essential variable.

 

If your PQR is not meeting the supplementary essential variable in case of low temperature service(Impact test requirement) you have to qualify a new PQR

 

eg 1: Your PQR is qualified with P1 Gr.1 material and your equipment is P1 Gr.2 material then you have to qualify a new PQR as group number is a supplementary essential variable.

 

eg 2: Your PQR is qualified in Flat position and the equipment require welding in vertical position then you have to qualify a new PQR at 3G position as position is supplementary essential variable.

 

Non essential variables meant a change from PQR does not call for new qualification

eg: Your PQR is qualified in double V joint and your equipment required single V joint, then you have not required to qualify a new PQR as joint design is mon essential variable.

 

You refer QW 250 in ASME sec IX for all variable applicable to each welding process.

 

Take your PQR and compare all the variables with the table provided in  QW 252. If it does not meet the essential/supplementary essential variable you have to qualify a new PQR.

 

I hope it will guide you to take a decision instead of giving a direct answer.

 

Regards,

 

Muhammed Ibrahim PK

 

 

 

Thanks & Regards
Muhammed Ibrahim PK

On 10 June 2010 14:54, Subrata Das <sdas@pkgroup.org> wrote:

 

 

 

From: Subrata Das [mailto:sdas@pkgroup.org]
Sent: Tuesday, June 08, 2010 12:11 PM
To: 'materials-welding@googlegroups.com'
Subject: Urgent quarry on filler wire selection and heat treatment after welding

 

Dear All

Can you all please guide me about the following confusion

I have conducted a PQR with base metal as A335 Gr.P91 to SB622 Hastelloy C276 N10276 with PWHT at 780 deg.C by GTAW process(Groove Weld Joint).

Now my job is A182 F91 to SB622 Hastelloy C276 N10276 with GTAW process and groove weld joint.

My quarry is that :

1.       Can I use filler metal as ER-NiCrMo4(SFA-5.14)/F.No.43.

2.       Shall I go for PWHT at 780 deg.C. or not necessary to do PWHT.

3.       Is it necessary to conduct mechanical test after PWHT as the job is a self equipment and not possible to destroy.         

 

Thank you with best regards

Subrata Das

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