Welding 12 Chrome Pipe

By 3.2 Inspector (***)

Date 08-31-2009 16:20

Is it the martensitic variant called X20?

3.2

By RButler (*)

Date 08-31-2009 17:10

Not sure at this point I will get more information regarding this material. I just wanted to get a few feelers out there to welders and people who have had expierence welding this material,so I can get an idea of what I am in for if we get this job.

By 3.2 Inspector (***)

Date 08-31-2009 18:06

If it is "ordinary" 12Cr it is not that much different than the 5 and 9 Cr alloys.
As always stringent welding and PWHT procedures most be followed punctly.

It is a good idea you ask the question again once you know the exact material you are dealing with.
There are PLENTY of experts here, but they need definitive questions :)

3.2

By RButler (*)

Date 08-31-2009 18:19

I will ask the question again when I have all the information.

Thanks R Butler

By G.S.Crisi (****)

Date 08-31-2009 18:17

3.2: being a German, you're not familiar with American standards. Nothing wrong, I don't know anything (or almost anything) of ISO and DIN standards.
12% chrome steel is martensitic AISI 410. 5% chorme is ferritic low alloy steel. 9% chrome is ferritic intermediate alloy steel.
The way to weld them is different. I've welded AISI 410 with ER 308 (first pass) and E 308-16 the subsequent passes.
Giovanni S. Crisi
Sao Paulo - Brazil

By 3.2 Inspector (***)

Date 08-31-2009 18:39

Thanks Crisi.
I guess that is what we call X20 in europe, or a close variant, in that case even more stringent PWHT procedures most be used.
I am not that well experienced in the material as it seem that P91 has taken over its usage on new construction.

If AISI 410 behaves as P91, I suggest that the Original Poster confrontes a well experianced welding engineer before even bidding on the job :)

3.2

By cwi49cwe (*)

Date 09-07-2009 01:19

We would all like to offer as much assistance in each others welding questions and problems, that is what makes forums so successful and enjoyable. Put all the facts out there in the beginning and a quick and accurate responce will develop. What is the grade of 4XX series, ferritic will not respond to heat treat for hardness, martensitic will and will definiately require a degree of preheat (how much and how long will be determined by , so far, unknown variables. Next consideration is what is expected out of the weld ???? If the weld has to respond to heat treat that the use of a 3XX series filler is out, waiting to see more info ........ and by the way, there are 5 and 9% chrome alloys out there the do require preheat and can be heat treated for hardness, very common in the tool and die industry.