'I'll,; Ferr;-.l nvpru[lr.:i, ·'f rhe ('_!,:l.sc-ic /(~ner lilUdEi bas been cot'rec-ted andrndevelop(~d for tlie ev,Llu.:~tlUd )f tlH~ !..'l,_l:,t"ji: ("oulributiofl to the thermodYllamlr'rnchart:lctl~t"j--'-~tic:~ uf diffusion nnd ;-~nJqi:ton (li ~;U1lf' intct":'3titial iHlpnritlesrn(11,N.C) in bee metals (~--Fe).rnequatioH have. been cl-ltic':1.J ty .nn;11y?cd .c1.nd QP_veloped. A thcoLt"!tic31 det..crip--rnt.lon of tll(:-~ gaHes pen.1H.:abLltt.y J.!lclltdfng both the diffus"lvity and solllhilityrnTh:U-;rntheon~tic£l t dpSCJ~ipttOll h:l:;; h::~cn u.':.;ed I·.d::h respec.t to the KnOoJl experilllentalrndatil on I he in_rlu~~Hcl~ of pr-iur cold--d,-d!.)rmatlon on the gaBt!.8 (ll},D?) pCflIleahllitrnt model hasrnbeen developed and i.n1pJr~ment~d lor ;"fudlng truc dJrru:-;ion c-oeftic.-ient1:: ofrn.1.iflPU1-iti.es .tn the ne2f--rJ(slol'at:i.on -se,t;fegdtioH rl~Kloo:-;; (NDSR) in 'ihich tlH~rcrnll:re 80[11(-' sU:lCnble eyper.:l.nwiltdl dZlt.a.rnSome infortnat.Jon OIl l:I'H? charach-,::_-i;~t tcs of tllP NlJSR has be(,;u obtainedrn·]hlch ShOHS that the NDSH. are not I!(~asy path H fOt: tmpurit.ie.s diffusion. ArnrelevmSK structure has been discussed