This flaw has not detected by 45/70 . Why?
This is inclusion , very difficult to detect because having same structural pattern which weld have, however multiple or bunching signals may seen in full scape probing but may not have distinct height. So we may neglect it. 70 degree side looking or 45 degree sc r meant for half moon & r unable to detect it, tandom may detect it, but signal’s r not so prominent because of its identical grain structure.
First clean that portion with k oil or petrol then only emphasize it properly