Please advice and suggestion from Aj.Methasit.
the preliminary investigation, we found that the surface is glossy appearance, size 3cm.X6cm.
When hardness testers found that high hardness measured 40.3HRC. - 50.6HRC.
I am not sure that the defect part is a problem from Hard spot , welding or Heat treatment process.
Please see are picture and report in attach file.