1.Qhov twg porosity defect nyob rau hauv txias-rolled coils los?
Porosity defects nyob rau hauv txias- dov coils yog yuav luag tag nrho cov qub txeeg qub teg los ntawm cov dej ntws tsis tu ncua nrum slab, originating los ntawm voids tsim los ntawm gases nyob rau hauv lub solidified steel thaum lub sij hawm steelmaking thiab nruam casting. Lawv tuaj yeem raug faib ua ob pawg:
Subcutaneous npuas: me me pores muab zais hauv qab ntawm qhov slab. Qhov no yog lub hauv paus ntsiab lus ntawm deg tsis xws luag nyob rau hauv txias- cov ntawv dov.
Pinholes / pores: Txawm me me pores los yog pores nyob rau hauv lub slab.
Raws li lawv lub hauv paus chiv keeb, cov pores no tuaj yeem muab faib ua argon npuas thiab cov tshuaj tiv thaiv pores (xws li CO npuas), thiab lwm yam.
2.Yuav ua li cas argon npuas tsim thaum lub sij hawm nruam nruam thiab thaum kawg ua rau tsis xws luag nyob rau hauv txias dov?
Bubble Generation: Thaum lub sij hawm nruam nruam, cov roj argon feem ntau yog cua tshuab los ntawm cov nres lossis lub taub hau saum toj kawg nkaus kom tsis txhob txhaws ntawm cov dej nkag nkag. Nyob rau hauv turbulent ntws ntawm cov hlau molten, cov roj argon no tawg ua npuas me me.
Bubble Entrainment: Feem ntau argon npuas nce mus rau saum npoo thiab yog absorbed los ntawm kev tiv thaiv slag. Txawm li cas los xij, yog tias argon ntws tus nqi tsis ruaj khov lossis qhov chaw ntws tsis raug tswj tau zoo, qee cov npuas argon yuav nkag mus tob rau hauv cov crystallizer nrog cov kwj dej molten steel thiab raug ntes los ntawm lub plhaub pob zeb, tsim cov pores subcutaneous.
Rolling Evolution: Cov pores subcutaneous no stretched thiab flattened thaum kub thiab txias dov. Yog tias cov phab ntsa pore tsis ua kom zoo thaum lub sijhawm dov, lawv yuav tawg lossis nthuav dav thaum ua haujlwm tom ntej, thaum kawg tsim tev, flaking, lossis dot- zoo li qhov tsis xws luag ntawm qhov txias - cov ntawv dov.
3.Nrog argon npuas, dab tsi lwm yam metallurgical yam yuav ua rau porosity?
Kev deoxidation tsis zoo: Thaum cov pa oxygen hauv cov hlau molten siab dhau lawm, lossis thaum tsis txaus deoxidizers (xws li txhuas lossis silicon) ntxiv, cov pa roj carbon - cov tshuaj tiv thaiv oxygen tshwm sim thaum lub sij hawm solidification, tsim cov pa roj carbon monoxide (CO) gas. Yog hais tias cov hlau molten muaj viscosity siab los yog solidifies sai heev, cov pa roj CO tsis tuaj yeem sawv thiab khiav, ua rau hauv cov pob zeb thiab tsim cov pores.
Gas supersaturation: Yog hais tias cov ntsiab lus ntawm yaj hydrogen, nitrogen, los yog lwm yam gases nyob rau hauv lub molten hlau yog siab dhau heev lawm, lawv yuav precipitate thaum lub sij hawm solidification vim poob sai sai nyob rau hauv solubility, muaj peev xwm accumulating thiab tsim pores.
Tsis zoo ziab ntawm nozzles los yog tiv thaiv slag: Yog hais tias cov slag tiv thaiv los yog nozzle cov ntaub ntawv uas siv nyob rau hauv nruam casting muaj noo noo, nws yuav tsim dej vapor thaum sib cuag nrog cov hlau molten nyob rau hauv kub kub, instantly tsim npuas uas yog nyob rau hauv cov hlau.
Cov kev tshawb fawb qhia tau hais tias cov khoom oxide qee zaum nrog cov npuas no, thiab tej zaum yuav raug tshem tawm thaum lub sij hawm tom qab pickling, tawm hauv qhov pores yooj yim xwb.
4.Yuav ua li cas porosity defects hloov zuj zus thaum lub sij hawm dov txheej txheem? Yuav ua li cas lawv thiaj li coj mus rau qhov txias -rolled coil?
Initial State: Nyob rau hauv tsis tu ncua slabs slabs, pores yog kheej kheej los yog ellipsoidal, xws li loj los ntawm microscopic kom pom ntawm qhov muag liab qab, faib subsurface los yog sab hauv.
Kub Rolling Stage: Nyob rau hauv qhov kub thiab txias siab dov lub siab, qhov pores yog flattened thiab elongated, ncua raws li dov kev taw qhia. Yog hais tias qhov pore nto tuaj yeem ua rau kev sib cuag zoo thiab sib txuas ua ke ntawm qhov kub thiab txias, qhov tsis xws luag yuav ploj mus; yog tias vuam tsis zoo, micro- delamination lossis tsis txuas ntxiv yuav tsim.
Cold Rolling thiab Annealing Theem:
Scale Formation: Unwelded subsurface pores yuav raug nthuav tawm los yog ze ntawm qhov chaw thaum lub sij hawm txias dov thinning, ua tus nplaig -zoo li bulges (ie, hnyav scale).
Kev Txhaum Cai: Cov pores hnyav lossis cov npuas npuas, thaum dov mus rau qhov nyias nyias, tsis tuaj yeem npog tag nrho los ntawm cov hlau, thaum kawg rupturing rau daim ntawv perforations.
Blister Formation: Cov roj uas nyob rau hauv lub sawb nthuav dav thaum lub sij hawm annealing cua sov, ua rau thaj tsam ntawm qhov chaw.
Daim ntawv kawg: Hauv cov khoom txias-cov khoom dov, porosity defects feem ntau tshwm sim li dot-zoo li los yog strip-xws li tev, ib qho los yog ntau lub qhov me me, thiab sib sib zog nqus.
5.Peb tuaj yeem txheeb xyuas qhov tsis xws luag los ntawm qhov pores ntawm ob theem macroscopic thiab microscopic?
Macroscopic Identification yam ntxwv:
Distribution Location: Cov teeb meem tshwm sim los ntawm argon npuas feem ntau yog faib rau ntawm cov npoo ntawm cov sawb (20-50mm los ntawm ntug), raws li cov npoo yog qhov chaw npuas yooj yim. Cov teeb meem tshwm sim los ntawm cov tshuaj tiv thaiv sab hauv pores tuaj yeem tshwm sim ntawm txhua qhov chaw hla lub strip dav.
Morphology tsis zoo:
Pit-zoo li Peeling: Pom me me, tsa cov dots uas tsis muaj qhov pom tseeb nyob ib puag ncig lawv; feem ntau nyob rau hauv siab - carbon steel los yog sib sib zog nqus - kos duab hlau.
Ib Qhov Me Me: Ib lub qhov me me uas cais tawm ntawm daim ntawv nyias; thaj tsam ib ncig ntawm lub qhov yog du, tsis muaj cov cim qhia ntawm kev tawg.
Microscopic Confirmation:
Metallographic Analysis: Ib qho hla- ntu yog txiav los ntawm qhov chaw tsis raug, hauv av, thiab pom. Peeling tshwm sim los ntawm npuas feem ntau qhia qhov tsis muaj dab tsi los yog delamination txuas ntxiv raws cov kev taw qhia dov hauv qab, tsis muaj qhov pom tseeb tsis yog -hlau suav nrog hauv cov matrix ib puag ncig.
Scanning electron microscopy (SEM) thiab zog dispersive spectroscopy (EDS) tsom xam:
Los ntawm kev qhib lub tev ntawm daim tawv nqaij los yog saib cov phab ntsa sab hauv ntawm lub qhov hws, qhov kev tshawb pom ntawm argon (Ar) ncaj qha ua pov thawj tias qhov tsis xws luag yog los ntawm argon npuas (txawm hais tias argon yuav tau dissipated, ua kom pom kev nyuaj).
Feem ntau, cov kab ntau ntawm cov oxides (xws li FeO, MnO, SiO₂, thiab lwm yam) raug kuaj pom, qhia tias cov pores underwent sab hauv phab ntsa oxidation ntawm qhov kub thiab txias.
Yog tias muaj ntau cov khoom tiv thaiv slag xws li Ca, Na, thiab K raug kuaj pom, nws qhia tau hais tias qhov tsis xws luag yog feem ntau tshwm sim los ntawm slag entrapment dua cov npuas yooj yim.
Cov txheej txheem tseem ceeb: Yog tias tsis muaj qhov loj ntawm macroscopic inclusions pom nyob rau ntawm qhov chaw tsis xws luag, tab sis lub morphology ua raws li cov yam ntxwv ntawm "txheej txheem, bubbling, thiab ib qhov pores," thiab qhov chaw nyob ntawm ntug los yog muaj keeb kwm ntawm argon entrapment nyob rau hauv tus txheej txheem, feem ntau nws muaj peev xwm txiav txim siab los ntawm porosity defect.