Gas Nitriding yog dab tsi?
Gas nitriding yog txheej txheem thermochemical deg hardening txheej txheem qhia hauv lub teb chaws Yelemees xyoo 1923 thiab tseem yog ib txoj hauv kev siv ntau tshaj plaws ntawm kev tsim cov hnav- tiv taus nto ntawm cov khoom hlau. Cov khoom raug thauj mus rau hauv lub qhov cub kaw thiab cov pa roj ammonia tau qhia, qhov twg nws dissociates ntawm qhov kub thiab txias rau hauv atomic nitrogen thiab hydrogen. Cov nitrogen diffuses mus rau hauv cov hlau nto thiab tsim nitrides nrog alloying ntsiab twb muaj nyob rau hauv cov khoom. Vim tias hardening nyob ntawm cov ntsiab lus ntawm cov hlau thiab tsis yog nyob rau hauv cov kauj ruam quenching, cov txheej txheem yog nqa tawm ntawm qhov kub thiab txias, distortion me me thiab tsis muaj kev kho cua sov ntxiv tom qab nitriding.
Kev kho mob feem ntau yog siv rau cov khoom uas yuav tsum tau tiv thaiv zawv zawg hnav, yaig lossis qaug zog thaum khaws cov tub ntxhais tawv, xws li lub zog, ncej, extrusion screws thiab chim, valve qhov chaw thiab cov khoom tuag.
Txheej txheem Parameters
| Parameter | Yam ntau yam |
|---|---|
| Kub | 500 txog 550 degrees Celsius |
| Huab cua | Ammonia, qee zaum diluted nrog dissociated ammonia lossis nitrogen |
| Duration | Kwv yees li 20 mus rau 100 teev, nyob ntawm qhov xav tau qhov tob |
| Txheej txheej | Cov txheej txheej ntawm kwv yees li 5 mus rau 25 micrometers hla thaj tsam diffusion |
Kev ua tau zoo ntawm cov txheej txheem nyob ntawm seb muaj pes tsawg ntawm ammonia tiag tiag dissociates ntawm qhov chaw. Cov pa roj ntau dua qis dua qhov kev sib cais, thaum qis qis nce nws; qhov kub siab dua kuj ua rau kom qhov sib txawv ntawm qhov sib txawv thiab txo nws ntawm qhov kub thiab txias. Vim tias lub cub tawg mus txog nws qhov ua haujlwm kub maj mam, lub peev xwm nitrogen thaum pib ntawm lub voj voog tuaj yeem sib txawv ntawm tus nqi thaum kawg, thiab cov ammonia dissociation yog li xyuas thiab tswj thoob plaws hauv kev kho mob. Ib lub voj voog ob -theem, nrog lub peev xwm nitrogen ntau dua thaum pib thiab qis dua tom qab, yog siv los txwv qhov tuab ntawm cov txheej txheej brittle.
Layer Structure thiab Properties
Nitriding tsim ib tug yam ntxwv ob txheej. Nyob rau saum npoo yog cov compound lossis txheej dawb, muaj cov hlau nitride theem, uas yog ib qho nyuaj heev tab sis kuj nkig. Hauv qab nws yog thaj tsam diffusion, nyob rau hauv uas nitrogen yog yaj thiab precipitated raws li zoo alloy nitrides, thiab uas muab lub qaug zog thiab load- bearing txhawb rau saum npoo. Ntawm nitriding steels cov txheej txheej hardness feem ntau yog nyob rau hauv thaj tsam ntawm 1000 txog 1200 HV, thiab cov ntaub ntawv qhov tob yog teev raws li daim ntawv thov, feem ntau nyob rau hauv cheeb tsam ntawm 0.1 hli mus rau 0.6 hli.
Lub brittleness ntawm txheej txheej yog qhov kev txwv tiag tiag. Ib txheej tuab dawb zoo li splell nyob rau hauv kev cuam tshuam kev thauj khoom thiab nyuaj rau kev zom, thiab qhov saum npoo yuav ntxhib thaum kho ntev. Qhov twg cov khoom raug cuam tshuam rau kev poob siab, cov txheej txheej feem ntau yog khaws cia nyias lossis tshem tawm tag nrho tom qab kev kho mob, khaws cia tsuas yog thaj tsam diffusion.
Cov hlau twg tuaj yeem ua Nitrided?
Nitriding nyob ntawm seb muaj nitride- tsim cov ntsiab lus hauv cov hlau. Aluminium, chromium, molybdenum thiab vanadium yog cov tseem ceeb, thiab cov qib uas muaj lawv teb tau zoo. Aluminium-cov kabmob nitriding steels xws li chromium-molybdenum- qib aluminium npog los ntawm GB / T 3077 yog qhov kev xaiv classic, thiab cov khoom siv Japanese xa khoom muaj xws li txhuas-chromium-molybdenum nitriding steel{9} kub kub, thiab chromium ua haujlwm kub feem ntau nitrided rau hnav tsis kam.
Ua ntej nitriding, cov khoom feem ntau yog quenched thiab tempered, los yog hardened thiab toughened, yog li ntawd cov tub ntxhais yuav tsum tau txhua yam khoom. Vim tias txhuas, chromium thiab molybdenum nce qhov kev hloov pauv kub, qhov kub thiab txias yog siab dua rau cov qauv hlau tiaj tiaj thiab qhov kub thiab txias kuj nce, yog li cov tub ntxhais tsis soften thaum lub sij hawm ntev tuav ntawm nitriding kub. Qhov thib ob yog vim li cas rau kev kho cua sov ua ntej yog temper brittleness: ntev cua sov ntawm nitriding kub tuaj yeem embrittle qee yam hlau hlau, thiab cov tempering yog xaiv raws li.
Daim ntawv thov thiab kev txwv
Extrusion screws thiab chim rau cov yas txhaj tshuaj molding tshuab, qhov twg cov seem pub thiab ntsia hlau ya davhlau hnav tawm tsam lub thoob.
Gears, cab shafts thiab splined Cheebtsam uas yuav tsum tau ib tug nyuaj nto nrog ib tug tawv core
Tuag thiab pwm Cheebtsam, coj bushes thiab ejector pins
Lub tog raj kheej liners, valve stems thiab twj tso kua mis qhov chaw, qhov twg muaj corrosion-resistant nto txheej yog zoo
Lub ntsiab drawbacks yog lub sij hawm ntev lub voj voog thiab qhov tshwm sim tus nqi, qhov tsis tshua muaj nitrogen efficiency ntawm ammonia cua, qhov ntxhib nto uas tsim los ntawm kev kho mob ntev, thiab qhov nyuaj ntawm machining txheej hardened tom qab. Cov nyiaj sib tsoo yuav tsum tau npaj ua ntej nitriding, thiab thaj chaw uas yuav tsum nyob twj ywm mos, xws li xov thiab nrhiav txoj kab uas hla, npog lossis tiv thaiv.
FAQ
Q: Dab tsi kub yog siv rau roj nitriding?
Gas nitriding feem ntau yog nqa tawm ntawm 500 thiab 550 degrees Celsius hauv qhov chaw ammonia, nrog rau lub sijhawm teem raws li qhov xav tau qhov tob.
Q: Vim li cas nitriding tsis xav tau quenching?
Lub hardening los ntawm nitride nag lossis daus nyob rau hauv txheej txheej, uas tsim thaum lub sij hawm kev kho mob nws tus kheej, yog li tsis muaj ceev ceev txias kauj ruam thiab yog li ntawd me ntsis distortion yog txuam nrog.
Q: Dab tsi yog qhov sib txawv ntawm cov txheej txheem sib xyaw thiab thaj chaw diffusion?
Cov txheej txheej yog nyias, nyuaj thiab nkig txheej txheej ntawm hlau nitrides; lub diffusion cheeb tsam hauv qab nws muaj yaj nitrogen thiab nplua hlau nitrides thiab txhawb cov txheej txheej saum npoo.
Q: Cov hlau twg yog qhov tsim nyog rau nitriding?
Cov hlau uas muaj nitride- tsim cov ntsiab lus xws li txhuas, chromium, molybdenum thiab vanadium, suav nrog cov chromium-molybdenum- qib aluminium thiab qee cov haujlwm kub tuag steels, teb zoo tshaj plaws rau kev kho mob.
Q: Vim li cas cov hlau quenched thiab tempered ua ntej nitriding?
Txhawm rau muab cov tub ntxhais xav tau lub zog thiab toughness thiab xyuas kom meej tias nws tsis soften los yog brittle thaum lub sij hawm ntev tuav ntawm nitriding kub.
Q: Dab tsi yog cov kev txwv tseem ceeb ntawm cov roj nitriding?
Lub sij hawm ntev lub voj voog, tus nqi siab, ib txheej txheej txheej uas nyuaj rau kev zom, thiab qhov roughened nto tom qab kev kho mob ntev.
