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Sub-contracting, pre-qualified materials

Sub-contracting, pre-qualified materials

Sub-contracting, pre-qualified materials

Hello, I am new to this group, I'm by no means a welding expert, but I am here looking for some expertise.

My business is production metal fabricating. We saw, laser cut, and weld parts together. Most of these parts go to an OEM of some sort. The part might go into farm machinery, trucks, it's all production weld work, designed by somebody else, going into somebody elses product. I don't really do any one-off things like a log splitter for the guy down the street, a bucket for the farmer across the street, or stairs for the new firehouse as examples.

I am attempting to get some new work. The weldment in question has been designed by the US Army. It has been built and in service for close to 20 years. The US Army buys a product from Company A. Company A buys the weldment from Company B. Company B makes one component of the two component weldment, sends it to me, I make the other component and weld both together, ship it back to company B who ships it to company A, who assembles the weldment into the product they sell to the Army.

The weldment has 2 components. One part is made from ASTM A572 gr 50, the other part is made from AISI 4130. They are joined together with (2) 1/8" fillet welds. The print issued by the US Army spells out those materials, weld sizes, and also states "weld in accordance with AWS D1.1/D1.1M".

I have requested a WPS from the CWI whom we normally work with. The CWI has come back to me and said that the 4130 is not a pre-qualified material. Therefore, in order to write a WPS, I first need to supply him with 4130 coupons, A572 gr 50 coupons, so that the materials can be welded together and tested/qaulified, in order to properly complete the WPS.

By the black and white code, I see how the CWI is coming to the conclusion that the material needs to be qualified. However, I'm questioning if it really has to be that way, if there aren't gray areas that a CWI could work with?

The print and the design of the part are the responsibility of the gov't, in the other words there is an engineer somewhere who has approved welding these 2 metals together. Through weld testing, or some other means, the engineer is saying these are qualified base metals. Could the CWI mark on the WPS, "PQR waived per US Army print XXX" or something like that?

How does the the code at D1.1, factor in? 4130 is a pre-qualified material in B2.1 if I'm reading it right. Rather than being re-active, could the CWI not push the information, and say on the WPS "using B2.1, per, to meet the D1.1 requirements on US Army print XXX" or again something similar to that?

I'm really not trying to get out of anything, and if I have to do the tests I'll do them. I just think it seems to be a waste to be testing all sorts of materials when I don't control the design. Thanks in advance for any input.  

RE: Sub-contracting, pre-qualified materials

If you are only making fillet welds, you can do a fillet weld only qualification per D1.1, which is not at all difficult.


I just think it seems to be a waste to be testing all sorts of materials when I don't control the design.

That is correct, but you do control the welding.  Therefore, because one of the materials is not "prequalified", you need to perform some testing that proves your welding conditions (ie, voltage, amperage) are adequate to produce the weld required by the customer.  That is all they're asking you to do when they say, "in accordance with D1.1".

RE: Sub-contracting, pre-qualified materials

Materials listed in B2.1 are not prequalified.

The 4130 is not prequalified per D1.1.

The CWI is correct in his assessment that you, the contractor doing the welding, are responsible to qualify the WPS. I'm not sure I agree with his position that you supply him with the materials and he qualifies the WPS (if I'm reading what was between the lines of your post).

The purposes of qualifying the WPS is to verify the mechanical properties are achieved and to demonstrate your process controls are functional.


Best regards - Al  

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