Waxaa jira noocyo kala duwanbirta kaarboon-yarqaybaha ujeedooyinka farsamada, habka codsiga dhabta ah wuxuu u baahan yahay sifooyin farsamo sare.Si kastaba ha noqotee, wax-soo-saarka dhabta ah, waxaan inta badan aragnaa in joogitaanka qaybaha birta-kaarboon-yar ee qaab-dhismeedku xiran yahay ka dib habka kulaylka.Sida qaab-dhismeedka banded waa birta ee urur cillad ah, marka qaab-dhismeedka band halis ah, sifooyinka farsamo ee birta anisotropy muuqata, tuubada birta si loo yareeyo hoos u dhac qaybta transverse more toosan iyo siman saamaynta tamarta tamarta ku saabsan farqiga double, caag ama birta adkaanta oo aan buuxin shuruudaha farsamada ee heerka.

Maaddada kaarboonka ee 0.10% ~ 0.35% ee birta kaarboonka yar ee dhalaalaysa ka dib inta badan si ay u maraan qallooca caagga ah (rogid, foorjo, balaadhinta kulaylka), ka hor intaanad noqon profiles.Si kastaba ha noqotee, ka dib markii la farsameeyo qaybo yar oo kaarboon kaarboon ah oo sahlan in la raaco jihada qallafsanaan, samaynta pearlite iyo ferrite wadooyin qaybinta aagga, kuwaas oo ah samaynta qaab-dhismeedka banded.Sababaha samaynta qaybaha birta-kaarboon-yar ee qaab-dhismeedku way kala duwan yihiin, oo lagu soo koobay laba sababood oo kala duwan:

(1) oo ay sababtay kala soocidda qaab-dhismeedka kooxda, taas oo ah, marka lagu daro qaybaha birta-kaarboon-yar ee ka kooban waqti go'an oo ka mid ah ka-qaybgalayaasha rog-rogista oo ay weheliso jihada duubista oo ka fogaysa qaybinta.Marka la qaboojiyo qaybo yar oo kaarboon ah oo kaarboon ah Ar3 hoose, wasakhdaas waxay noqdeen eutectoid ferrite nucleation ka dhigi eutectoid ferrite inclusions agagaarka jiilka kowaad ee foomka qaybinta zonal, ka dibna jirka austenite haraaga galay pearlite, lagu arkay hoos mikroskoob heerkulka qolka, ferrite waa caddaan. , madow cawl iyo pearlite, taasoo keentay in naadi cad iyo madow, taas oo ah cillad yar oo bir kaarboon ah unugyada.

(2) qaab-dhismeedka band by heerkulka processing kulaylka ay sababto aan habboonayn, in processing kulaylka ee qaybaha birta kaarboon hoose si ay u joojiyaan foorarsiga heerkulka wakhtiga aagga laba-weji ah (inta u dhaxaysa A1 iyo A3), ferrite weheliyaan jihada socodka ee birta ka soo roobka austenite austenite, burburka austenite weli lama gooyn xariijin, marka la qaboojiyo A1, austenite strip galay band pearlite.