cryogenic weld procedure testing of stainless steel

Date 07-22-2009 16:58

If you are doing Charpies that cold you may well want to consider low/or no ferrite weld metals. It is exactly what they are designed for. GTAW will most likely not cause any concern but if you use fluxed processes this is what I would recommend.

By tim johnson Date 07-22-2009 19:33 Edited 07-22-2009 19:55

js55;

Thanks for the reply.

What designation is given to such filler metals? I have some 308ULC in stock, would that be considered low/no ferrite?

By js55

Date 07-22-2009 20:53

There is no generic or AWS designation for such. It will be identified by brand labels. Consult your supplier.
Euroweld has the most knowledgeable people I know of for this application.

By jon20013 (*****)

Date 07-23-2009 12:05

Tim, first of all, you shouldn't have any problem with the base metal at the temperatures referenced. Secondly, js55 gives great advice and further, if you have access to an ASME Section VIII, Division 2, there is some excellent information regarding austenitic filler metals exempted from impact testing at very low temperatures. Of course, this isn't to say you would be exempted in your instance but if you look at the filler materials mentioned they are provided exemption because in most instances they have ultra low temperature characteristics which yield impacts as nearly meaningless. One example, while it may or may not work in your case would be ERNiCrMo-3 (just an example!).

An exerpt:

(2) For austenitic weld metal:
(a) having a carbon content not exceeding 0.10% and produced with filler metals conforming to SFA-5.4, SFA-5.9, SFA-5.11, SFA-5.14, and SFA-5.22 at MDMTs of -155°F (-I04°C) and warmer; etc.

By fludnor Date 08-18-2009 04:33

js55 is correct. for considering SS welds in the cryogenic service, choose the 308L types for whatever process that you would prefer BUT look for those consumable manufacturers that guarantee a low or controlled ferrite feature. i attended a product introduction from Metrode and they have one.you may check them out. i remember them presenting CVN values of 100J at the -196ºC range. best regards!

By crashproj (*)

Date 07-24-2009 07:51

Tim,

You don't have to worry making a welding procedure for stainless steel with CVN requirement tested at minus 196 deg. C. 304L match filler metal with 308L and monitor interpass temperature during welding of test pipe. also purging gas should be maintain until the weld joint completed this is for material thickness less than 10mm. for higher thickness maintain purging gas up to 6 to 8 mm weld deposit.

regrds

By CWI555

Date 07-24-2009 13:15

http://www.aws.org/cgi-bin/mwf/topic_show.pl?pid=65093;hl=ferrite%20
You can use the search function of the forum for more info.

By rodofgod (**)

Date 08-15-2009 09:35

Hi All!

What about Lateral Expansion tests?

Regards

By js55

Date 08-17-2009 12:44

What about them?
There can be some information garnered from LE but most codes utilized impact strength. Exceptions are for example, Section III and some LE tests for certain alloys.
LE emhasizes ductility as opposed to strength.

By Shane Feder (****)

Date 08-18-2009 02:42

Rodofgod,
Most requirements for Lateral Expansion will be written into the project specifications, I have never seen it as a code requirement.
If the specs require it then it would be an additional test performed on the PQR coupon.
All our s/s PQRs on a recent LNG project required LE tests,
Regards,
Shane

By js55

Date 08-18-2009 12:37

Shane,
ASME III requires lateral expansion testing, as well as B31.3 for carbon and low alloys of 95ksi or more and for P6, 7, and 8 materials.

By motgar

Date 08-17-2009 13:49

Tim,

I see you note this as an ASTM/ASME weld procedure. Do you mean the material is dual certified?

Only raising the question based on the numbering for qualified materials. If the material is ASTM: A240 Type 304L then, you will only get a S-number. If the material is ASME: SA-240 Type 304L then, both the P-number and S-number are covered. I think it is listed under QW-420.2

Also remember sombody saying that S-numbers are not approved for pressure boundary applications.