C45 material welding

[smart143]

I have to weld C45 material with A106 Gr B pipe.Design code is B31.3.since no P number assign to C45 per sec IX,my existing P1 to P1 qualification will not suffice.
C45 material is 50 mm thick and will be welded to 12.7 thick A106GRB pipe by fillet weld.
I am chosing E7018-1 electrode for welding with min preheat as 300 deg C.
Do i need to take any other precaution to qualify this joint.

 

[DVWE]

300C? That is on the high end of preheat. Do you mean 300F? That is more realistic for this material.

Use 7018-1H4R for improved resistance to hydrogen cracking.

How big is the fillet weld? You still may want to consider post weld heat treat if it is large enough.

 

[smart143]

are you proposing 150 deg c preheat only?

fillet weld throat is 12.7 mm.....does it need PWHT per B 31.3?
i will qualify first butt weld cupon per QW 451 of sec IX

 

[DVWE]

smart143,

Yes, that is what I am proposing. 150C minimum preheat and 300C maximum interpass temperature should be adequate.

That size of fillet weld should not require PWHT according to B31.3