Akwai iri-irilow-carbon karfesassa na injiniya dalilai, ainihin aikace-aikacen aikace-aikacen yana buƙatar babban kaddarorin inji.Duk da haka, a cikin ainihin samarwa, sau da yawa muna samun cewa kasancewar ƙananan sassa na ƙarfe na carbon sun haɗu da tsarin bayan aikin thermal.Irin wannan tsarin banded karfe ne a cikin wani lahani kungiyar, a lokacin da tsanani band tsarin, da inji Properties na karfe bayyana anisotropy, da karfe bututu don rage transverse sashe shrinkage more a tsaye da kuma a kwance tasiri makamashi tasiri makamashi game da bambanci biyu, filastik ko karfe. taurin baya saduwa da buƙatun fasaha na ma'auni.

A cikin carbon abun ciki na 0.10% ~ 0.35% na low carbon karfe smelting zubo a bayan mafi rinjaye don shiga ta hanyar nakasar filastik (mirgina, ƙirƙira, haɓakar thermal), kafin zama bayanan martaba.Koyaya, bayan sarrafa ƙananan sassa na ƙarfe na carbon mai sauƙin tafiya tare da nakasawa shugabanci, samar da pearlite da ferrite hanyoyin rarraba shiyya, wato samuwar tsarin banded.Dalilan samuwar ƙananan ƙarfe na ƙarfe na ƙarfe na ƙarfe sun bambanta, an taƙaita kusan dalilai iri biyu:

(1) lalacewa ta hanyar rarrabuwa na tsarin band, wato, lokacin da hada ƙananan sassa na ƙarfe na carbon ya ƙunshi wani adadin lokacin mirgina haɗawa tare da mirgina shugabanci nesa da streamline rarraba.A lokacin da sanyaya zuwa wani low-carbon karfe sassa Ar3 a kasa, wadannan ƙazanta zama eutectoid ferrite core nucleation sa eutectoid ferrite inclusions a kusa da ƙarni na farko na zonal rarraba nau'i, sa'an nan saura austenite jiki a cikin pearlite, lura a karkashin microscope a dakin zafin jiki, ferrite ne fari. , Baƙar fata mai launin toka da lu'u-lu'u, wanda ke haifar da farar fata da ratsan baƙar fata, wanda shine ƙananan ƙwayar ƙwayar ƙwayar ƙwayar ƙwayar carbon.

(2) da band tsarin ta thermal sarrafa zafin jiki lalacewa ta hanyar da bai dace ba, cewa thermal aiki na low carbon karfe sassa don dakatar da ƙirƙira zafin jiki a lokacin da biyu-lokaci zone (tsakanin A1 da A3), ferrite tare da kwarara shugabanci na karfe daga hazo na austenite, bazuwar austenite ba a yanke shi cikin tsiri ba, lokacin da aka sanyaya shi zuwa A1, tsiri austenite cikin rukunin pearlite.