dissimilar metals

By PWCameron (**)

Date 04-25-2012 00:39

???

You tell us. Who is the welding being done for? What is the customers requirement?

PWC

By welderbrent (*****)

Date 04-25-2012 01:35

Martin,

WELCOME TO THE AWS WELDING FORUM!!

I'm with PWC, we really need a little more info here.

But, off hand, I would venture that you are working to D1.6 even if it is generally under D1.1. Once you go to a stainless you are going to have to utilize both if I remember correctly.

Now, your job specs/contract documents are probably going to give you some of your answers. As will the type of joint, type of job, and other considerations.

More than likely you will find this definitely has to be qualified by testing which means the first welder is qualified by testing and then testing procedures are set up upon successful qualification of the procedure and establishment of a WPS.

NDT will be a combination of joint details with applicable code and contract documents.

Have a Great Day, Brent

By 803056

Date 04-25-2012 03:15

Question one: What welding code or standard are you working to?

My response depends on the specific code requirements and the requirements differ from one code to another. To provide some examples of the differences between the codes, let's briefly look at AWS and ASME.

In the case of D1.1 or D1.6; the combination of CS to SS is not prequalified. Therefore the Engineer (representing the Owner) must approve the WPS which must be qualified by testing. Once the WPS is qualified, the welder must be tested using (following ) the qualified WPS.

In the case of ASME, Section is most likely applicable. The WPS must still be qualified by testing and then the welder can be qualified. ASME is different than AWS. In the case of Section IX, it is permitted to substitute certain base metals, so in this case it is possible to qualify the welder following the quaified WPS, but you can use either CS to CS or SS to SS or CS to SS provided all the essential variable that pertain to welder performance qualification are observed. In this case the F-number must be the same as that listed in the qualified WPS. The use of backing is an essential variable as wll as test position when qualifying the welder. There are other things to consider, but you can do that leg work yourself.

Best regards - Al