How to Improve Charpy Results for 3.5% Ni Steel? 1

[iam42]

Help!!!

I have just ran a PQR for welding 1" Thk A203 Gr.E Plate. The Impact requirements were 15 ft/lbs at -150 F.

The results were:

Weld C/L Cap 10,8,9
Weld C/L Root 9,8,17
HAZ Cap 27,29,21
HAZ Root 53,67,164

I welded the plate with GTAW,SMAW and SAW. The consumables were ER80S-Ni3, E8018-C2 and ENi3/Lincoln 860 flux respectively.

I set a pre-heat of 300F and an Interpass of 600F.

How can I improve the Impact results?

PS the tensile, bends and hardness survey were all good.

Thanks

 

[vesselfab]

i always weld the coupons down to a thick plate to help "suck away" the heat.

Heat is death to charpys

better control of interpass temp (paramount)

should have passed

 

[metengr]

I would use smaller size weld passes with minor overlap between beads. The objective is to provide for grain refinement in the base metal HAZ, and keep heat input localized.

 

[iam42]

Guys,

Would it be wise to reduce the pre-heat? Also, is there anything I can do with the PWHT. The failed plate was PWHT'd at 1100-1175F for 1hr.

Thanks

 

[stanweld]

The 860 flux for SAW is not adequate to provide the toughness required.

 

[iam42]

Stanweld,

Do you have a suggestion for an alternative?

Thanks

 

[weldtek]

I've used 880M down to -80F. I'd suggest you contact Lincoln's technical applications people for a recommendation. 800-839-5462 ask for technical assistance

 

[GRoberts]

My first comment was going to be the 860 flux as well. The first ones I would look at are 880M or 888, or some ESAB fluxes would work as well, but I don't recall off the top of my head. If you are outside the US, Orlekon makes OP121 (SP?)o, make sure you have an experienced pipe welder that is able to keep the root pass heat input to a minimum. On the SMAW, you can also get better results with 7015-C2L instead of 8088-C2 all other things being equal. Champion makes a good 7015-C2L. I don't have any data available at the minute though.

 

[stanweld]

Bohler had the only flux filler combination rated at -150F. If in the US, contact them at 800-527-0791.