| Dear Ahmed, Kindly note that it's not recommended to Weld SA335 Grade P91 (Chromium Moly steels) to Carbon Steel SA106 Grade B for many reasons : There'll be high tendency for the carbon atoms in the carbon steel to migrate to Chromium Moly steel to combine with the Chromium (Due to high affinity of carbon to chromium ) which in turn will softens the carbon steel to some extent ,Embrittle the HAZ & MAY result in depleted zone with very poor Mechanical Properties .( This carbon migration process is a Diffusion Metallurgical Phenomena which mainly depends on Temperature & Time and that's why it will happen during two stages during Welding Cycle itself & during PWHT which'll be mandatory for P91 steel). From Design Point of View there's a high Strength Mismatch between the two Materials & the carbon steel SA106 Grade B will not Mechanically Perform like SA335 Grade P91 neither at room temperature nor at Operating Temperature which definitely will be high temp more than 350C ( that's why SA335 Grade P91 had been selected for your application ) Tensile Strength of Carbon Steel SA106 Grade B @ 25C is 414MPa & @ 500C is 285MPa. Tensile Strength of Low Alloy Steel SA335 Grade P91 @ 25C is 586MPa & @ 500C is 410MPa. Regards Mohamed.Hegazy F.S.I Coordinador AWS Certified Welding Engineer CWEng. TWI CSWIP Welding Inspection 3.1. AL JABER Power & Energy Projects.
QATAR SHELL PEARL GTL Project
Ras Laffan ,Qatar QATAR : +9743694501 EGY: +20142345614 Email : MH_w_INSPECT@YAHOO.COM | Tensile Strength of Low Alloy Steel SA335 Grade P91 @ 25C is 586MPa & @ 500C is 410MPa. Mohamed.Hegazy F.S.I Coordinador AWS Certified Welding Engineer CWEng. TWI CSWIP Welding Inspection 3.1. AL JABER Power & Energy Projects.
QATAR SHELL PEARL GTL Project
Ras Laffan ,Qatar QATAR : +9743694501 EGY: +20142345614 Email : MH_w_INSPECT@YAHOO.COM |
--- On Mon, 6/21/10, Ahmed Hafez <diesel2002@hotmail.com> wrote:
From: Ahmed Hafez <diesel2002@hotmail.com>
Subject: RE: [MW:5683] weld SA-106 to 9 Cr materials P No 5B gr 1 or gr 2
To: "Welding Material" <materials-welding@googlegroups.com>
Date: Monday, June 21, 2010, 2:59 PM
but P91 must be heat treated with temp. range 700-760 deg celsius with no exemptions as per table 132 ASME 31.1 require PWHT at temperature and the lower phase transformation temperature for carbon steel is 723 deg celsius . and temp. range for PWHT for CS is 600-650 deg celsius which is very far from P91 temperature ranges and consequaently make the weld joints to fail in hardness test requirements.
Date: Mon, 21 Jun 2010 04:45:24 -0700 From: kashkousha1@yahoo.com Subject: Re: [MW:5682] weld SA-106 to 9 Cr materials P No 5B gr 1 or gr 2 To: materials-welding@googlegroups.com dear ahmed yes,by using ER 90S-B9(GTAW)&E9018-B9 (SMAW) or E 9015-B9 the joint should be heat treated acc .to ASME B31.3 H.KASHKOUSHA
From: Ahmed Hafez <diesel2002@hotmail.com>
To: Welding Material <materials-welding@googlegroups.com>
Sent: Mon, June 21, 2010 1:42:17 PM
Subject: [MW:5681] weld SA-106 to 9 Cr materials P No 5B gr 1 or gr 2
good morning every one is it applicable to weld SA-106 to 9 Cr materials P No 5B gr 1 or gr 2 thanks and best regard
Your E-mail and More On-the-Go. Get Windows Live Hotmail Free. Sign up now. -- To post to this group, send email to materials-welding@googlegroups.com To unsubscribe from this group, send email to materials-welding-unsubscribe@googlegroups.com For more options, visit this group's bolg at http://materials-welding.blogspot.com/The views expressed/exchnaged in this group are members personel views and meant for educational purposes only, Users must take their own decisions w.r.t. applicable code/standard/contract documents. -- To post to this group, send email to materials-welding@googlegroups.com To unsubscribe from this group, send email to materials-welding-unsubscribe@googlegroups.com For more options, visit this group's bolg at http://materials-welding.blogspot.com/The views expressed/exchnaged in this group are members personel views and meant for educational purposes only, Users must take their own decisions w.r.t. applicable code/standard/contract documents.
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