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Up Topic Welding Industry / Technical Discussions / welding of 9% Cr to C/S
- - By alisharif (*) Date 01-19-2005 08:01
Dear sir
For weding between two pipe with dissimilar material(%9 Cr and carbon steel)Do we must use carbon steel electrode such as E6010 & E-7018 or another electrode? I saw in ASME that we must use electrode according to lower alloy of joint.

best regards
A.A.Sharif
Parent - - By Shane Feder (****) Date 01-20-2005 04:31
Ali,
API Welding Guidelines for the Chemical, Oil and Gas Industries recommends Carbon steel welded to 9% Chrome to be welded with
E70XX or E80XX-B7/ E80XX-B7L low hydrogen electrodes.
AWS Recommended Practices for Welding of Chromium-Molybdenum Steel Piping and Tubing recommends E7016/E7018 for SMAW and ER70S-2/ ER70S-3 for GTAW,
Hope this helps,
Regards,
Shane Feder
Parent - - By alisharif (*) Date 01-23-2005 12:45
Dear Feder
Can we use E-6010 for root pass ?or we must use only low hydrogen electrode for root and other passes?
best regards
A.Sharif
Parent - - By MBSims (****) Date 01-23-2005 17:52
I've seen a number of questions like this recently here that are beginning to worry me. I would caution anyone that uses the internet in lieu of knowledgable engineering staff that this is like rolling the dice for safety. I see numerous questions here dealing with piping, pressure vessels or structures that should be handled by persons with a thorough understanding of the codes, material properties and welding practices. In most places, installation and repairs of piping and vessels requires a code certificate of authorization and/or quality program that ensures the finished product is safe. If one is using this forum as a sounding board or educational tool, that is OK. But if one is taking technical info from an unknown internet source as being sound technical advice and implementing it without verifying it with knowledgable engineering staff, then lives of workers and surrounding neghborhoods are being risked.

For instance, 9Cr is a martensitic steel. Why would anyone want to use a cellulose-type electrode for the root pass in a martensitic steel when it is so susceptible to hydrogen cracking? 9Cr also requires PWHT. If CS weld metal is used, there will be carbon migration from the weld metal to the 9Cr side of the joint during PWHT. Carbon loss in the weld metal means lower weld strength. Will it be enough to cause the weld to fail? Has the procedure even been qualified? Let's roll the dice and find out!
Parent - - By Shane Feder (****) Date 01-24-2005 03:40
MB Sims,
I appreciate your concerns and agree with the majority of your statement but take issue with certain comments.
Firstly,
" taking technical info from an unknown internet source as being sound technical advice." I took that information verbatim from AWS and API publications sitting in front of me.
Secondly,
I have spent 12 years as a CWI with a lot of this time involved in third world countries ( Papua New Guinea, Fiji, Vanuatu, Kiribati and the Solomon Islands).Some of the stories regarding quality control (or lack of) I could tell you would make you cringe.
Dodgy work has been happening for years (and not just third world countries) and will continue to happen in the future.
There is a possibility that 6010s have been used in the past for welding this material and the consequences (worst case scenario) could prove to be catastrophic.
I think this gentleman has already made "the lives of workers and surrounding neighbourhoods "safer by actually asking the question and not just going ahead and welding with whatever they found the most convenient.
Believe me, it does happen!
Regards,
Shane Feder
Parent - - By Shane Feder (****) Date 01-24-2005 03:54
Marty,
My apologies. I responded to your post prior to reading the second posting from Ali Sharif.
I now see what you were meaning, Technical expertise ( Welding Engineers,Metallurgists etc) should always be involved when making critical engineering decisions.
Regards,
Shane Feder
Parent - - By alisharif (*) Date 01-24-2005 06:23
Dear Feder
You dont answer my question about using of E-6010 for root pass?

best regards
A.Sharif
Parent - By jon20013 (*****) Date 01-24-2005 13:27
Dear Mr. A.Sharif;

I my experience, I would strongly recommend against using an E-60 series electrode for the root pass. I believe Mr. Feder gave you very sound advice regarding API Welding Guidelines for the Chemical, Oil and Gas Industries. Having corresponded personally with Mr. Feder before, I have a great respect for his opinions.
Parent - - By MBSims (****) Date 01-24-2005 11:36
Sorry if it looked like I was taking issue with your response Shane, that was not my intent. I also hope no one else thought I was questioning their responses or their background and experience. I am concerned that some folks are relying on this forum as their engineering dept. When an accident occurs, are they going to say they thought it was accurate and reliable since it was obtained through the AWS website? Or will they try to hold the persons responding responsible? The majority of questions I see here seem to be folks wanting to increase their personal knowledge, but a number of recent requests don't fit that description.
Parent - By jon20013 (*****) Date 01-27-2005 20:32
Marty; I don't think any court in the land would hold any of us responsible for responding with what we believe to be good engineering judgment. This is, after all, simply an open forum and is not as you correctly point out, anyones engineering department. Personally, myself having over 30 years in the welding field, I've come in here numerous times to either ask questions or get a second opinion on something that could be construed as seeking engineering advice. As I'm sure you're aware, in our field many people consider themselves "experts" until they've been in the field long enough to realise just how little they actually do know and I quickly add myself to that latter category!
Parent - By George-kh (**) Date 02-06-2005 20:22
As Sim said, "If CS weld metal is used, there will be carbon migration from the weld metal to the 9Cr side of the joint during PWHT". So for high temprature, more than 400C I think, a nickle base alloy filler must be used, not to let carbon migration.
Ali, may you tell us ASTM designation of your carbon and 9%Cr steels?
Parent - By gerold (*) Date 01-25-2005 19:52
Could you please reference where in the ASME Code that states using the lower alloy electrode, I am unfamiliar with such a requirement? I had recently qualified an ASME WPS for 2 1/4Cr, 1Mo (P5A) to 9Cr (P5B) using ER80S-B6 for an open root and E8018-B6 filler with a PWHT.

Thanks,

Chris Gerold
- - By TAHIR ALI KHAN Date 11-08-2019 06:05
Dear sir
For welding between two pipes with dissimilar material(% 13Cr and carbon steel A106). Kindly guide me about electrode for SMAW and filler wire for GTAW.
Parent - By Jim Hughes (***) Date 11-08-2019 14:05
TAHIR ALI KHAN,
Would need to know more info about this "13%" Cr. material. Can you give anymore info on it? i.e. chemical comp. ASTM number or ASME number or UNS number. Secondly, you are responding to a post from 2005. The insight given in that original 2005 post was inaccurate at best and totally wrong at worst. Thirdly, whatever you choose to do, a pup piece of 2 1/4 Chrome should be put between the 13% Cr. and the C.S. , or at least considered.  I would recommend that you research though EPRI (Electrical Power Research Institute) for current information on welding this type of material. Even if this work is not in the Power Industry, they are the most up to date on filler metal and process control means and methods than anyone right now. API is way behind and a lot of their info is outdated on this subject. My opinion anyway.
Up Topic Welding Industry / Technical Discussions / welding of 9% Cr to C/S

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