P1 to P8

HI

FIRST GIVE ME THE SERVICE TEMPERATURE TO SELECT THE PROPER FILLER,

ACC TO YOUR CASE, USE ER 309 ONLY FOR THE ROOT AND FILLING.

QA/QC ENG: AMR SOLIMAN

PETROJET-EGYPT

No. On the other hand , you can use ER 309L for root welding as well as 2nd pass application and balance by SMAW process using E 309L electrode, if the thickness is on higher side (to reduce the cost factor) or by GTAW itself if the material is less than 6 to 8 mm thick.

Type 309 with 25Cr and 12 Ni, is most suitable for joining austenitic stainless steel to carbon steel (like A 106) or low alloy steel (for service temperatures less than 300⁰C) as it contains high amount of alloy content( Cr & Ni) to prevent martensite formation in the weld metal after total dilution by the two base metals and to retain some amount of ferrite in the final austenite weld metal to prevent hot cracking.

The undiluted ferrite content in 25Cr & 12 Ni type 309L type metal is about 6-10% and much more than what is present in 19-13 Mo type 316L filler wire or electrode.

you can check up Schaeffler diagram for further details.

Sridhar.