D1.5 filler metal/flux combinations-pqr

By EVEREADY Date 08-31-2001 05:53

My company has an on-goning debate in regards to SAW qualification. Specifically, if we do a PQR for SAW using Lincolnweld 960 flux/LA-75 (AWS Calssification F8A2-ENi1k-Ni1-H8) on AASHTO M270 Gr.345W for unpainted structural members and it passes all of the mechanical and chemical requirements in subsequent destructive testing, does that PQR also qualify Lincolnweld 960 flux/L-61 (AWS Classification F7A2-EM12k-H8)? There is one school of thought that is of the opinion that table 4.3 Note 1 allows for this. There is another school of thought that is of the opinion that Table 4.3 Note 1 has nothing at all to do with the subject of qualifing one flux/filler metal which in turn "automatically" prequalifies the use of a lower tensile strength (i.e. Qualifying F8 "automatically" qualifies F7) flux/filler metal. There is yet another school of thought that says that Table 5.1 negates the whole debate since it implies that for each different classification of filler metal a new PQR must be done. The argument against this is that Section 5.5 is intended to refer to the MANUFACTURER'S responsibility to test and certify filler metals annually and the CONTRACTOR'S responsibility to gather material certifications that attest to the fact that the manufacturer did indeed qualify its filler metal/flux combinations to meet AWS A5.23 or AWS A5.17 (latest edition) and it does not refer in any way to the CONTRACTOR'S PQR or WPS, other than the fact that the contractor must have a MTR on the filler metal before a PQR can even be done. This makes sense sinse Section 5.4 is along those same lines in dealing with base metal. Without a doubt this is a difficult interpretation to get a group of people to agree on. I would appreciate any comments or suggestions on this. If anyone has run into this same debate and has found a suitable solution please let me know. Thanks.

By BankerQC (*)

Date 08-31-2001 15:18

Hello Everready,
at my shop we tend to try to err on the side of the "safe" interpretation whenever possible. Ergo, as listed in table 5.3(D1.5-'95) a change in electrode flux combination is considered an essential variable which requires re-testing. Also contained in that table is a requirement to re-test any change in electrode classification. I have not reviewed a newer addition of the code recently in regard to this. Also depending on whom the work is being performed for, they may wish to have some input regarding this. In some states The DOT provides or stipulates a list of approved electrodes that should be considered. These may or may not be "pre-qualified" based on thier interpretation and opinions.
Also of note may be wether or not the work that you are doing is considered fracture critical , if so that can open a whole new can of worms. Hope maybe this helped a bit , Im no expert but I am learning and just trying to pass on some of what I have had to learn in the last few months. If I can be of any further assisatance, please feel free to contact me.

By CHGuilford (****)

Date 08-31-2001 17:25

I would say that Table 5.3 Numbers 8 means you would not be able to qualify both wires with the same test. As you have indicated, you will have 2 different electrode-flux combinations. The EM12K and ENi1K are significantly different.

Also, Table 5.1 lists WPS qualification requirements. 5.5 does apply to the manufacturer but 5.5.1 and 5.5.2 apply to WPS qualification. That is the contractor's responsibility, not the electrode/filler metal manufacturer's.

Table 4.3 means that if you are welding Gr 50W steel, the weld metal must achieve a Ni1, Ni2........ or W chemical analysis in addition to meeting applicable requirements of Tables 4.1 or 4.2. Note 3 talks about, again, the contractor's responsibility.

I don't think section 5.4 helps in the arguement that Table 5.1 refers to the manufacturer because 5.4 is only giving the direction that base metal used for WPS qualification must meet certain requirements. It means the contractor must make sure the metal used is in conformance or else the entire test will be unacceptable.

Actually, it sounds to me like some of your folks are getting some D1.1 prequalification requirements mixed up with D1.5. My interpretation is that you need 2 PQRs. (I don't think 960 / L-61 will even achieve a Ni x or W analysis, will it?)

Hope this helps
CHGuilford