Hello Sirs,

I have a big problem Butt Welds - Single Bevel with not having backing bar (HV Forms) welding inspection.Welding process is MIG,MAG.
I always take welding root pass echos. I can't separe the flaw echo beucase of the root echo. Thinckness is 8mm for both steel.
Material is S690. I used Krautkramer USM 35X. 60 and 70 degree 4 Mhz probs.

I try to use 80 degree probes for find the failure at 1st leg.

Or is it possible to anybody help me how can I inspect and write the procedure about this inspection. ?