General comments:
1) If welding is governed by ASME, you will more than likely require a new procedure qualification (PQR) and WPS. C1 electrodes are A Number 10 (See QW-422) and most likely the E7018G will be either an A Number 1 or not be in within any A Number classification ranges. (A Number is an essential variable for SMAW - see QW-253 which lists QW-404.5 as essential)
2) Since C1 electrodes have nickel addition, they have superior impact resistance (low DBTT and higher absorbed energy) than typically obtained with electrodes without Ni.
3) You will sacrifice some strength as specified minimum tensil is 10ksi (~70 MPa) greater for C1 relative to the E7018G
4) Most welding guides for welding of P355NL2 recommend a Ni added electrode - more than likely to match the impact properties
So, if I were your customer, I would want you to verify the design requirements; tensile strength, yeild strength, and minimum design metal temperature (to determine impact test parameters) and then perform a new procedure qualification to demonstrate that the required properties are met. Note that it is common customer requirement when a "-G" electrode or filler metal is employed, that the resulting WPS will be limited to the electrode or filler metal of the same manufacturer and brand name/type.
Hope this helps.
John
From: materials-welding@googlegroups.com [mailto:materials-welding@googlegroups.com] On Behalf Of Hamed Malekan
Sent: Wednesday, June 03, 2009 7:37 AM
To: materials-welding@googlegroups.com
Subject: [MW:2314] PQR for P355NL2
want to select the E 7018G (Esab) for welding the material P355NL2 .already we weld this material with 8016C1 (KOBE) but our client need some evidence for example somewhere PQR result to allow to use 7018G. I checked all properties & I can use . If I want to use 8018C1 the corrosion problem in base metals near the weld area will happened & other matter is the less price of 7018G compare with 8018C1. Anty body can give me some help in this case? Thanks H.Malekan Mechanical Manager LPG tank ( South Pars Gas Field in IRAN) |
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