TheX-raydiffractionpeak-shiftmethodwasintroducedintothedeterminationofdeformationfaultprobability(α)ofFe-Mn-SialloyswithvariousMncontentsandthermomechanicalcyclingnumbers.Thepreciselatticeconstantsrequiredwereobtainedbynumericalcalculationinsteadofusingstandardsamplewithoutanyfault.Theinfluenceofinternalstressonthedeterminedαhasbeenevaluated,andthecausedrelativeerrorwasdeterminedasabout4%andthusnegligible.TheresultsshowthatthedeformationfaultprobabilityincreaseswithdecreasingMn-contentandincreasingcyclenumber,whicharequalitativelyconsistentwiththoseresultsofPsfdeterminedbypeak-broadeningmethod.
