Question about filler materials 1

[andygo11]

Hi, I met a problem on WPS regarding filler materials. According to WPS we have, ERNICRMo-10 is specified (Section II, Part C SFA-5.14). The vendor is using ERNICRMo-3 instead because both of them have the same F number. So, they believe the two filler materials can be interchangable. Is that true? Thanks.

 

[andygo11]

Forgot to mention it is GTAW. I saw F and A number are both essential varibles. But in my WPS, there is no A number available.

 

[gtaw]

The A number only applies to ferrous metals. Assuming the contractor is welding a nonferrous alloy, the A-number is not an essential variable to consider.

Just because the code may allow a contractor to do something is not justification to do something that is not reasonable from an engineering standpoint. There are many things to consider in addition to the essential variables listed by ASME Section IX. For instance; Joint detail is not a consideration, i.e., it is not an essential variable for the GTAW process. If the contractor qualifies the WPS using 1 3/4 inch thick material, the range of thickness qualified extends to 8 inches. While Section IX does not consider joint details as an essential variable, I believe most people recognize that switching from a V-groove with a 60 degree groove angle to a square groove with no root opening and using GTAW with a 3/32 inch diameter tungsten has little probability of success if the base metal thickness is 5 inches thick.

ASME has no provisions for common sense. The following essential variable does not appear in Section Nine: Does This Make Sense? The person making decisions must be competent and understand weld technology.

Best regards - Al

 

[XL83NL]

excellent point gtaw, well put. a star for that!

 

[metengr]

ASME has no provisions for common sense. The following essential variable does not appear in Section Nine: Does This Make Sense? The person making decisions must be competent and understand weld technology

True, but then again, if you would have read the foreword you would know that ASME Boiler and Pressure vessel codes and standards are not handbooks for design and fabrication. Weld joint design such as a compound bevel are found in other publications.

 

[gtaw]

Good point. That is one more aspect of a code many people don't understand.

Best regards - Al

 

[pandithan]

If u make weld plan/weld map, u can avoid this kind of mistakes. Appreciate gtaw(Structural0 for clean explanation
Pandithan

 

[jwhit]

My understanding of the code is that a new PQR would not be required, but a new weld procedure supported by the original PQR should be written to cover the change in filler metal. You cannot arbitrarily switch them out, but you can switch them if the change is documented. Whether or not it's a good idea is a subject of another debate.
The ERNiCrMo-3 seems to be the go to filler when issues like this crop up.

 

[vanci]

In my opionion, altering filler metal types with in the same F-number grouping is the same as altering base metals of the same P number and expecting the the final product to meet all design requirements. As others have stated, the WPS is not the only document that needs to be complied with.

 

[stanweld]

From a design for service standpoint, the weld filler metals are not interchangable. From a Section IX standpoint, qualification with any F43 filler metal qualifies for all F43 filler metals.

If the Purchaser specified ERNiCrMo-10 for production welding, the Manufacturer may not substitute ERNiCrMo-3.