which hardness was reduced? That of SA387 or that of the cladding?
What was the normalization temp? 900 deg?
Was the cooling after the normalization done at still air or it was done under the insulation? if you heated at 900degC and then cooled slowly under insulation, then you have recrystallized and increased the grain size, so metallurgical properties have been deteriorated
The cladding risk sensitization if the ss is not stabilized with Ti. You have to check the cladding to check if chromium carbides have precipitate to the grain boundaries