SA 213 T2 - 309 OVERLAY ( FURNACE WALLS )

[JIPMKWA]

Good morning,

The customer wants their furnace walls overlayed where we installed new panels. The panels are already overlayed with inconel 622 and they tie into existing panels that were previously overlayed with stainless ( I think a 309 stainless of some sort ).

I told them that they should use NiCrMo-10 ( P3 with F43 overlay pulsed spray GMAW) for this but they wanted to use stainless because it is cheaper to buy for near the same life expectancy.

We do not have a P3 with A8 stainless overlay procedure for GMAW , only a P4 with A8 procedure using FCAW. I am not an overlay expert but I didn't think FCAW was good for overlay purposes and you use solid wire ? The only P3 with A8 procedure we have is using SMAW ( 309L-16 ). Needless to say it is slow going.



I guess my questions are ,

1. I know we need a WPS qualified but in your experience , is it acceptable to Overlay P3 material with ER309 solid GMAW wire ?

2. Is our procedure for welding P4 with FCAW 309-LT1 even remotlety acceptable for overlay welding to P3 ?

 

[metengr]

1. I know we need a WPS qualified but in your experience , is it acceptable to Overlay P3 material with ER309 solid GMAW wire ?

I would not recommend 309 because of the concerns with carbide formation along the fusion zone of the weld overlay and the linear coefficient of expansion differences.

2. Is our procedure for welding P4 with FCAW 309-LT1 even remotlety acceptable for overlay welding to P3 ?

No. You really need to review ASME Section IX, QW-255.1 for corrosion resistant weld overlay essential variables.

 

[weldstan]

You can be assured that cracking of the 309 overlay will occur when welding over the 622 alloy overlay. So if the customer insists on using 309, be sure to clue him in that you will not be responsible for any of the repairs that will be incurred.