[MW:3363] R: 3361] Re: Heat Input

Jeremy,

 

The use of cellulosic electrode for low temperature carbon steel is not quite appropriate. Sometimes and especially nowadays there some product classified as E6010 that can bear CVN at -46°C. I don’t know the diameter of root pass electrode, the WT you have used for PQR nipple, but I think that the weld metal deposited by cellulosic electrode is not more than 2mm. When you are extracting the CVN specimens, you will never test them the root pass. Then you are not sure that the E6010 will resist at -46°C. This risk will be increased if you are using high heat input.

If you are using this type electrode, you are increasing the risk to have hydrogen cracks especially in the root. I would suggest to use GTAW or low hydrogen electrode (E7016-1) for the root pass.

 

Regards

 

F

 

 

 

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Da: materials-welding@googlegroups.com [mailto:materials-welding@googlegroups.com] Per conto di Jeremy Zibin
Inviato: martedì 29 settembre 2009 9.56
A: materials-welding@googlegroups.com
Oggetto: [MW:3361] Re: Heat Input

 

Gentlemen, We've used qualified welding procedure specifications for LTCS that specifiy a root layer of 6010 (but only 1 root layer and no hot-pass) and then fill and cap layers with 7018.  This welding was performed on pressure piping under B31.3 for use in Northern Canada (min. design temp. of -46C).  The WPS was qualified, stamped by professional welding engineers and approved by the client. It is my understanding that the root lay is limited in thickness on the WPS and therefore the total thickness and properties of the full weld are majority 7018, which is approved for LTCS.  The heat input is limited to a max. on the WPS so that the welded joint should have the adequate impact properties at low temperatures.  This will be proven during qualification but remember not to limit yourself on heat input on the WPS, use a typical heat input for your welding process and material thickness to pass the qualification.   Regards,   JZ   --- On Mon, 9/28/09, Muhammed Ibrahim <ibratech@gmail.com> wrote: From: Muhammed Ibrahim <ibratech@gmail.com> Subject: [MW:3358] Re: Heat Input To: materials-welding@googlegroups.com Received: Monday, September 28, 2009, 11:16 PM E6010 will support up to -29 degree celcius only and used in pipe line root application. But if the PQR passes the impact you can use it with batch restriction. regards, Ibrahim 2009/9/29 BHARAT GOLE <bharatgole@hotmail.com> E 7018-1 is acceptable up to -46 degree but selection E 6010 is not suitable for LTCS ! As per which clause it is selected for LTCS ? Regards Bharat B. Gole   Date: Tue, 29 Sep 2009 09:49:23 +0530 From: nach_sam@yahoo.com Subject: [MW:3354] Re: Heat Input To: materials-welding@googlegroups.com Adi, Heat input is a guideline for subsequent welding. The yardstick is the average  value as obtained from your PQR. Your production welding should not exceed PQR HI values. By the way, is 6010, 7018-1 Ok for LTCS?  What is the working temp? Shashank Vagal --- On Tue, 29/9/09, Adi <adinraos@gmail.com> wrote: From: Adi <adinraos@gmail.com> Subject: [MW:3352] Heat Input To: "Materials & Welding" <materials-welding@googlegroups.com> Date: Tuesday, 29 September, 2009, 9:35 AM I have done the PQR for LTCS by using 6010 & 7018-1 as per ASME SEC IX some time i got 5KJ heat in put What is the limitation for heat input and where it is mention? Adi From cricket scores to your friends. Try the Yahoo! India Homepage!</a   Get easy photo sharing with Windows LiveT Photos. Drag n' drop     -- Thanks & Regards Muhammed Ibrahim PK   Be smarter than spam. See how smart SpamGuard is at giving junk email the boot with the All-new Yahoo! Mail </a

 

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