By using the Mossbauer spectre

the chang6 of cobment and structure of the retained austenite have been studied for A-B ductile iron under the tensile strain and recycle fatigue Btrain.It is shown that content of the retained austenite decreases with increasing strain and the micro-structure of the reclined austenite can be resolved intO two kinds of strictMe:one with and the other without C atoms arotmd Fe atoms.The existential carbon atoms eDter the interstices of the Fe fee sbocfore.The r.elative percentage of the two kinds of sboctnye depends on the strain and treshoellt Process.