Dissimilar of Materials

[aws2004]

Dear all,

Please give me a suggestion for welding of dissimilar materials Sa 335 Gr P 91 and A 106 Gr B.

What is the correct material to perform welding joint about(ER / E)?

Best regards.

Magalhães Julio

 

[metengr]

This combination of dissimilar material needs a transition piece of P22 in between the carbon steel (P-No 1) and Grade 91 (P-No 15 E Group 1). I am assuming the maximum service temperature will be governed by the carbon steel pipe material.

I would recommend welding the A 106 to A 335 Grade P22 transition piece and weld using the GTAW root with SMAW fill ER80S B2/E8018 B2. Once this is completed and PWHT, if required, I would weld the SA 335 Grade P22 piece with a 5% Cr filler metal to the Grade 91 pipe material.