PQR/WPS - AWS A5.1 E7015 / 7018

[Tuga29]

Our contractor issue their PQR's and WPS's according to ASME IX.
They choose for some of them AWS A5.1 E7015 electrode. From what I can understand this is the first type of low hydrogen electrodes and now it was mostly replaced by E7018 that contains iron powder in the covering.

We will ask them why did they choose E7015 instead of E7018, but I would like to know if we can force them to use the E7018 in the construction (qualifying the welders with that electrode)? It's the same F-number (4).

We have the following construction codes:
ASME B31.3/B31.4 - Piping and Pipeline
API 650 - Aboveground Tanks
AWS D1.1 - Steel Structures

 

[weldstan]

There is no essential variable change so either can be used in both the WPS and the Welder Qualifications. You can force them to use the E7018 since the contractor could ask for additional cost due to contract change but why bother? Weld quality would not be affected. Somewhat greater deposition will occur with the E7018 but if your contract was fixed price it wouldn't matter. E7018 is not better than E7015 0r E7016.

 

[Tuga29]

There isn't a major cracking issue with the E7015 electrodes? They are almost out of the market for what I can see.

 

[metengr]

No major cracking issue. Agree with weldstan.

 

[Tuga29]

Thank you both.