Sour service qualification for WPS 1

[engr2GW]

Hello everyone,
I have a few questions about qualifying a welding procedure for sour service.I'm fairly new, but I understand that the main course of action that eliminates the need for post weld heat treatment for ASME B31.3 piping welding is the use of lower hydrogen electrode, and then doing the NACE harness survey on the metal, HAZ, and weld area of the weld.
1. Can someone help recommend electrode types that are considered low hydrogen and good enough for this? This is for carbon steel, of strenght no higher than 57k or above.
. Also, a guideline for pre-heat treatment?

Thanks

 

[stanweld]

Refer to API 582, Section 12.

 

[engr2GW]

Thanks Stanweld,

I looked at it and it talked about the required hardness test, and the positions where the survey is to be taken, but it does not talk about selection of electrode (filler metals) that can be used on a preliminary WPS to fulfil that harness test.

I was looking for a guide to filler metal selection, such that the weldment and coupon can pass the sour service test. Thank you.

 

[stanweld]

Assuming SMAW process, use E7015, E7016 or E7018 electrodes. All are A-1 analysis, low hydrogen electrodes. Today, all have low carbon equivalents

 

[Duwe6]

Stay with E7018. And be aware that there is quite a variation between brands. This variation shouldn't affect your final hardness, but I usually take the extra step of specifying brand. For non-Xray/UT work, Lincoln's LH70 is a very good choice and moderately priced. For X-ray/UT work, EASB's AtomArc is still the industry standard. However is is also more expensive, but that this cost disappears into the "big picture". Both will give deposits of about BHN 185, and have a history of never having caused any problems.

 

[stanweld]

mysarah,
Preheating to meet hardness in the base metal HAZ depends on thickness and carbon equivalent. Assuming that you are qualifying the procedure on P1 group material without PWHT, I would recommend 200 F to 300 F. All the better if you can maintain a 450 F to 600 F interpass temp for the capping passes.