The iron contains {HEAD ~ alloying elements} that enhance the high temperature thermal fatigue and {TAIL ~ hot oxidation resistance} in service 
The iron contains { HEAD ~ alloying elements } that enhance the high temperature thermal fatigue and { TAIL ~ hot oxidation resistance } in service
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH REL OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH