By Fahmee
Date 10-19-2008 04:32
its not recomended to use FCAW for this joint. You might use GTAW + SMAW to get better hardness result. FCAW will contribute high heat input in your weldment. If you joint AISI 4130 to X52 material, you will having a problem when 4130 welding need PWHT but X52 not. I have suggestion as below;
1) weld this two different material and perform PWHT after. You may face drop on YS on X52 material. your joint design eng has to consider this.
2) perform buttering on 4130 with CS/LAS filler that can perform PWHT then you can close joint with X52 material without PWHT.
you can use ER80S-G & E8018-D2 with nickel content <1%.
Two good FCAW wires on the market for 4130 Mud Pipe. Select Arc's Select 101SR and Hobart's Fabco 107G. Good weld ability and all position use. Use a 300 degree F Preheat, Interpass Temp. not to exceed 400 degrees F. Any ER80S-D2 GTAW for root and 2nd pass will do. Weld FCAW for balance using only stringers with no beads larger than the tip of your pinky finger. This prevents cracking and heat input issues. PWHT at 1125 degrees F for 2 hours per inch of thickness and slow cool. This will result in great YS, TS and impact properties plus a Rockwell C hardness between 20 and 22 for the NACE Sour Gas Service requirements. Been doing this for the last 5 years or so.
