13Cr WELDABLE MARTENSITIC STEEL

[chitessy]

Goodday Everyone,

Please, any one that have been involved in the welding of a gas line of pipe material: 13Cr weldable martensitic steel. I will sincerely appreciate your advice and if possible any draft pWPS that could be of help and guide. I have had suggestive inputs from senior colleagues but I need advice from someone who has practically been involve in the welding of 13Cr weldable martensitic steel gasline.

Thanks sincerely
chitessy

 

I believe you are referring to 13-4 stainless, which indeed is weldable, but there are serious pitfalls if it is not handled appropriately.
I suggest you call in an expert welding engineer possessing actual experience with this alloy.

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

 

[kingnero]

https://www.eng-tips.com/viewthread.cfm?qid=304849

https://www.eng-tips.com/viewthread.cfm?qid=431675

Both may contain some interesting information.

 

[Hatstrow]

What kind of advice are you looking for?
Some basic stuff and depending on code: You will have to maintain an interpass weld temperature around 400-500F and then you'll have to PWHT at around 1380F . Matching filler will work but having something with a little more Ni in it would help stabilize the Austenite before it transforms to martensite on cooling, giving you less ferrite. The high Cr to low Ni will make ferrite come out quite a bit and generally you don't want to exceed 20%, otherwise your toughness will drop.

Also, typically, I think people do a GTAW root pass and then fill it up with SMAW.


Hope that helps at lease a little,

 

You will have to maintain an interpass weld temperature around 400-500F

At the very maximum

and then you'll have to PWHT at around 1380F.

absolutely Not
.



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

 

[Hatstrow]

Ironic,

Could you explain why not PWHT?
Are you assuming his is talking about 13-4? which I would understand is a ferritic steel.
I guess I was was thinking more along the lines as 410, which I know they use in the oil/gas industry.

 

I did not state 'not PWHT'.
13-4 aka CA-6NM aka 415 is unlike all other martensitic stainless grades.
For more info you will need to google.

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

 

[chitessy]

Good-day All,

Thanks to all for all your inputs. The material in question is SEAMLESS STAINLESS STEEL LINE PIPE 13%CR-2.5%MO. We will have to put up a pWPS, and carry out the procedure qualification process to see what happens.

Thanks to all
Chitessy

 

[weldstan]

These martensitic stainless pipeline grades were derivatives of CA6N as per ironic metallurgist. Welds can be made without PWHT if the carbon content is very low. Bohler Thyssen has low carbon filler metal that we used to qualify a procedure without PWHT but we did not use it for production welding. Didn't get the project.

 

13%CR-2.5%MO is a curve ball, but then I have had little contact with upstream oil & gas. It will be unlike the 13Cr-4Ni that I had assumed.
I would expect the response to heat treatment and the welding issues to more like those for 410SS.
I would contact the pipe manufacturer and perhaps a weld consumable supplier for specific fabrication advice.

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

 

[EdStainless]

These are actually ferritic alloys.
When you get the carbon low enough for weldability they hardly form any martensite.
Does your procedure require passing impact toughness? at low temp? That is often the hard part.

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P.E. Metallurgy, Plymouth Tube

 

[chitessy]

ironic metallurgist (Materials)
Just like you suggested, we were able to get advice for the welding consumables.

EdStainless (Materials)
For this procedure, impact toughness test is not required.

Thanks All

 

[pradipgoswami]

Chitessy,
Please refer this link below. Welding of this steel with all pros and cons are well explained. Best properties in welding of this steel are achieved,with matching welding electrode and adopting PWHT.
Thanks.

http://www.metrode.com/SiteData/en-gb/File/410 Types.pdf

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

 

[chitessy]

Thanks pradipgoswami for the document.