wherein {HEAD ~ the damaged location} of the region near the surface contains {TAIL ~ a degradation} of a microstructure whereby that at least a specific microstructural portion falls below a required concentration, 
contains
wherein { HEAD ~ the damaged location } of the region near the surface contains { TAIL ~ a degradation } of a microstructure whereby that at least a specific microstructural portion falls below a required concentration ,
OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH