Inconel overlay procedure is qualified by using 4 mm dia electrode for first layer and further layers with 5 mm dia electrode.

As per Sec IX QW>253.1,404.38 change in nominal diameter used for the first layer of deposit is non essential varriable.

Now our situation is, that we want to deposit with 4 mm electrode for all the layers.We are reqesting the experts to interpret the above and kindly do reply.

T.S.Kannan.India

"non essential varriable" is the key and no other variables (essential or supplementary essential variables) are showing for this variable so it would seem you could deposit with 4 mm electrode for all the layers but to be "clean" you should make an editorial revision to your WPS or perhaps issue another WPS indicating 4 mm electrodes for entire overlay.

In my opinion, it is showing first layer as a non essential varriable to flag up that increasing diameter may cause un-wanted dilution in the overlay.