Stability Of Alloyed Cementite And Saturation Magnetization Of Tire Cord Steel From VES Calculations

Based on the empirical electronic theory of solids and molecules(EET),the actual model of cementite(?-Fe3C)was built and the valence electron structures(VES)of cementite with specified type,site and number of Fe atoms substituted by alloying atom of M(M=Cr,Mn,Mo,W,V)were computed by statistical method.After influencing factors of stability of alloyed cementite were analyzed by VES,defining P as the stability factor,the changing law of P as a function of numbers of Fe atoms replaced by M and the most stable structure of alloyed cementite were attained.The saturation magnetizations(Ms)of tested steel and alloyed cementite were calculated from VES,and the calculation results are in good agreement with that of VSM experiments.The order of dissolution of alloyed cementite was determined by analyzing the stability,the four stages dissolution model of alloyed cementite was then built and the effect of cementite dissolution on the Ms of tested steel was given.VSM results show that Ms of the severely cold drawn sample changes dramatically due to the huge change of magnetic moment of Fe atoms in ferrite.The atomic states of Fe in tested steels at different strains were calculated from EET.