Lub dissolution tus nqi ntawm carburizing cov neeg ua hauj nyob rau hauv molten hlau ncaj qha txiav txim siab lawv nqus efficiency thiab zaum kawg nqus tus nqi.
Qhov no yog ib tug complex physicochemical txheej txheem, feem ntau cuam tshuam los ntawm cov nram qab no yam:
Cov hauv qab no yog cov ntsiab lus tseem ceeb uas cuam tshuam rau qhov kev sib cais ntawm cov neeg ua haujlwm carburizing, teev nyob rau hauv kev txiav txim ntawm qhov tseem ceeb:
I. Kub (Thermal Factor)
Qhov no yog qhov tseem ceeb tshaj plaws thiab tseem ceeb tshaj plaws.
• Lub hauv paus ntsiab lus: Lub dissolution ntawm carburizing cov neeg ua hauj rau hauv molten hlau yog ib tug endothermic txheej txheem, yuav tsum tau nqus cov cua kub ntau.
Qhov kub siab dua txhais tau tias:
Tsawg viscosity ntawm molten hlau: zoo fluidity, uas yog zoo rau lub convection thiab diffusion ntawm carbon atoms.
Kev ua kom muaj zog ntawm cov pa roj carbon atoms: ntau dua lub zog kinetic, ua kom yooj yim rau kev tshem tawm ntawm tus neeg sawv cev carburizing thiab diffuse rau sab hauv ntawm cov hlau molten.
Accelerated solid-kua interface cov tshuaj tiv thaiv: siab dua kub muab lub zog thermodynamic tsav zog.
• Kev cuam tshuam tus qauv: Tus nqi tawg nce siab nrog qhov kub thiab txias.
Tshaj 1500 degree, qhov kev sib cais yog ob peb zaug sai dua li ntawm 1400 degree.
II. Khoom Properties ntawm Carburizing Agents
1. Qib Graphitization:
• Cov graphitized carburizing cov neeg ua haujlwm siab: Lawv cov pa roj carbon atom yog npaj rau hauv cov ntawv xaj graphite, zoo ib yam li cov qauv graphite hauv cov hlau cam, yog li nthuav tawm zoo dua wettability nrog cov hlau molten.
Molten hlau tau yooj yim dua "ntub" rau hauv qhov khoob ntawm cov nplooj ntawv graphite, ua rau lawv tev tawm ntawm txheej txheej, ua rau muaj kev sib cais sai dua.
• Tsis yog-graphitized (piv txwv li, calcined petroleum coke): Cov qauv carbon tsis zoo thiab ntom, ua rau cov dej tsis zoo nrog cov hlau molten. Molten hlau muaj qhov nyuaj nkag mus, thiab kev sib cais feem ntau yog nyob ntawm qhov qeeb qeeb, ua rau qeeb qeeb.
2. Particle Loj thiab Zoo:
• Particle Size: Muaj qhov pom qhov loj me me (feem ntau yog 1-5 mm).
Cov khoom zoo heev: Yooj yim ntab rau ntawm cov kua dej, ua rau kub hnyiab heev-tawm thiab lub sijhawm luv luv nrog cov hlau molten.
Cov khoom loj dhau lawm: Cov cheeb tsam me me tag nrho, thiab yooj yim rau hauv qab, ua rau thaj chaw me me nrog cov hlau molten thiab lub sij hawm tawg ntev.
• Cov porosity: Porous, xoob carburizing agents (xws li qee qhov qis -cov neeg ua haujlwm zoo carburizing) muab ntau txoj hauv kev nkag mus rau cov hlau molten, uas ua rau pib tawg sai sai, tab sis tej zaum yuav ua rau tus nqi qis qis vim qhov kub hnyiab sai - tawm.
III.Molten Iron Condition
1. Chemical Composition ntawm Molten Iron:
• Carbon Saturation: Qhov ze dua cov ntsiab lus ntawm cov hlau molten yog rau nws cov saturation concentration (txiav txim siab los ntawm carbon equivalent CE), qhov tsis muaj zog ntawm "tsav tsheb" rau cov pa roj carbon dissolving, thiab qhov qeeb qeeb ntawm kev tawg.
• Cov ntsiab lus "Blocking":
Silicon (Si): Lub ntsiab thaiv kev tiv thaiv.
Silicon txo cov solubility ntawm carbon nyob rau hauv molten hlau thiab adsorbs mus rau saum npoo ntawm carburizing tus neeg saib xyuas, tsim ib tug thaiv txheej uas txo cov dissolution tus nqi. Qhov no yog vim li cas tseem ceeb vim li cas carbon yuav tsum tau ntxiv ua ntej silicon.
Manganese (Mn): Muaj qhov cuam tshuam me me thiab tuaj yeem tshem tawm qhov tsis zoo ntawm cov sulfur los ntawm kev cuam tshuam nrog sulfur los ua MnS.
• "Txhawb" Cov ntsiab lus:
Sulfur (S): Nyob rau saum npoo, sulfur reacts nrog cov pa roj carbon monoxide los yog hloov qhov nro, cuam tshuam kev sib cais.
Qhov tseem ceeb tshaj, leej faj txo cov wettability ntawm molten hlau nrog recarburizers (tshwj xeeb tshaj yog graphitic carbon), ua raws li ib tug muaj zog inhibitor ntawm dissolution tus nqi.
2. Flow thiab stirring ntawm Molten Hlau:
• Txoj Cai: Muaj zog convection thiab nplawm tuaj yeem:
Tshem tawm sai sai cov pa roj carbon monoxide- nplua nuj txheej nyob rau saum npoo ntawm lub recarburizer, nthuav tawm cov chaw tshiab rau kev sib txuas ntxiv.
Tiv thaiv lub recarburizer los ntawm agglomerating thiab nyob, kom ntseeg tau tias nws cov yam ntxwv faib nyob rau hauv lub molten hlau.
• Txoj kev: Electromagnetic stirring nyob rau hauv nruab nrab - zaus induction rauv yog ib txoj kev zoo heev.
Phau ntawv stirring kuj muaj qee qhov cuam tshuam.
IV. Kev Ua Haujlwm
1. Txoj Kev Ntxiv:
• Ntxiv hauv qab: Lub recarburizer yog them los ntawm lub cub tawg thiab pib yaj maj mam los ntawm thawj lub sij hawm cov hlau molten melts. Txoj kev no muab lub sijhawm so kom zoo tshaj plaws thiab tshwm sim nyob rau hauv qhov qis dua - qhov kub thiab txias, uas ua rau muaj qhov kub hnyiab tsawg heev -tawm thiab tag nrho cov kev sib cais thiab kev nqus tau zoo tshaj plaws.
• Ib nrab-Cycle Ntxiv: Ntxiv thaum lub pas dej molten twb muaj lawm, tsis txhob pib hlawv-tawm. Dissolution cia siab rau electromagnetic nplawm, ua rau tus nqi nrawm dua.
• Nto Sprinkling: Txoj kev phem tshaj.
Thaum cov carburizers raug kub thiab huab cua, ib qho tseem ceeb hlawv tawm, thiab lawv ntab rau saum npoo, ua tsis tau zoo tiv thaiv cov hlau molten, uas ua rau muaj qhov tsis tshua muaj txiaj ntsig zoo.
Los ntawm kev nkag siab thiab tswj hwm cov xwm txheej no, qhov kev sib cais ntawm cov carburizers tuaj yeem txhim kho tau zoo, yog li ua tiav cov txiaj ntsig zoo, ruaj khov, thiab qis dua -cov nqi carburizing.
