Change in Electode Filler Wire Classification with Impact Test PQR 2

[ukmet]

Dear Experts,

I have PQR for LTCS with filler wire ER-80S-Ni2 with impact test at -46C. I need to prepare a WPS for sour gas piping project with impact test at -46C which require nickel content should not be more than 1% in welding consumable. So considering the requirement of QW-404.12 if I change the consumable to ER-80S-B2 will it fall under change in classification?

Thank in advance.

 

[weldstan]

Yes. However, ER80S-B2 will no doubt not meet the impact toughness requirements.

 

[ukmet]

What could be the possible solution without qualification of new PQR?

 

[DekDee]

Purchase electrodes with less than or equal to 1% Ni.
A quick scan of google showed 2 x manufacturers with typical Ni of 0.87 %
Another 2 with max Ni of 1.0%

 

[david339933]

Not sure I understand Shane....ER80S-Ni2 has 2.0 - 2.75 Ni by spec.

 

[DekDee]

My mistake David - was looking at the ER80S-Ni1.
Somebody remove that star please

 

You need nickel for low temperature impact toughness.
ER-80S-B2 is not an acceptable or equivalent swap; besides it will never pass Cv testing @-46C.

It used to be assumed that nickel addition was death to steel in sour service, but now up to 1% is considered acceptable in at least some environments. I have a paper on that, but it is unavailable to me at this moment (meaning I lost track of it after several PC changes.

Bigger picture: you need to retain an engineer with oil & gas corrosion knowledge, and at least one of welding and steel metallurgy. Otherwise you are playing with fire.

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

 

[ukmet]

Thank you ironic metallurgist. A WPS can be made with impact test mentioning ER80S-Ni1 when the PQR is qualified with 80S-Ni2. This is my question that what could be the possible options without qualifying a new PQR.

 

[SJones]

One option could be to enquire as to whether -46 deg C is the actual minimum design temperature of the piping, or whether the piping engineer has looked at ASTM A333 and said to themselves, "Charpy tested at -46 therefore my piping minimum design temperature is -46 - even if the material will never go below, say, -20"

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/in/drstevejones

All answers are personal opinions only and are in no way connected with any employer.

 

[ukmet]

I will look in to it if that is the case or not.

 

[M.CH]

Hi UKMET,

ASME IX is a general code and is not comprehensive code for special job such as sour service. Sour service job need more engineering/corrosion consideration and i recommended that do your job based on sour service specification. severity of fluid and amount of H2S,Co2,water,PH,NACE 0175 region, temperature may affect the rigor in the choice of welding material, requirements and consequent qualification and required tests.

you can find below note:
1- 80S-Ni1 is good choice for Low temperature service @-46 oC.
2-80S-B2 has not designed for LTS. Mo content is added to increase creep resistance and to be suitable in high temperature service in boiler and same areas and is not recommended for sour service fields.in other hand Cr content is not good for sour service.
3- if 80S meets the design requirements in terms of strength, it is a good choice, provided that the manufacturer has produced it specially for sour service (unless qualify by test). Select the minimum acceptable strength level of welding consumable, for instance 70s-xx,if applicable/relevant.
4- As I read in a paper, 0.70 Ni content is optimum for sour service( i can't find that) and Ni content more than 1% is restricted or not recommended.
5-As "ironic metallurgist" said "Bigger picture: you need to retain an engineer with oil & gas corrosion knowledge, and at least one of welding and steel metallurgy. Otherwise you are playing with fire."

Best Regards,