Ferro silicon nitride, feem ntau sau FeSiN, yog nitrogen bearing ferroalloy ua los ntawm nitriding nplua ferrosilicon hmoov nyob rau hauv kev tswj kub. Lub hauv paus ferrosilicon ua raws cov qib tsim xws li cov uas tau teev tseg hauv GB / T 2272, thiab cov nitrogen yog cov tshuaj sib xyaw ua ke hauv nitride es tsis yog nqa raws li roj. Thaum cov khoom ntxiv rau molten hlau nws decomposes thiab tso tawm silicon thiab nitrogen nyob rau hauv cov nqi tswj, yog li lub foundry tau txais ib tug graphitizing keeb thiab ib tug ntsuas nitrogen ntxiv los ntawm ib tug ruaj khov ntxiv es tsis txhob ntawm ob txoj kev kho mob.
Hom Kev Sib Sau thiab Qib Xaiv
| Parameter | Hom kab mob | Muaj nuj nqi hauv Cast Iron |
|---|---|---|
| Silicon | 45 - 55 % | Graphitizing keeb, txhawb ferrite thiab nodule tsim |
| Nitrogen | 18 - 25 % | Refines graphite, nce nodule suav, stabilizes pearlite |
| Aluminium | 1.5% max | Khaws qis kom txwv tsis pub muaj roj muaj feem xyuam rau hauv cov ntu hnyav |
| Cov pa roj carbon | 0.5% max | Khaws qis kom carbon tswj cov yaj tsis cuam tshuam |
| Particle loj | 0.2 - 1 mm, 1 - 3 mm, 3 - 10 mm | Matched rau ladle, hauv -pwm los yog kwj inoculation method |
Qib xaiv pib los ntawm lub hom phiaj nitrogen ntawm cov yaj thiab cov ntu tuab tau nchuav. Hnyav seem nrog qeeb txias yuav tsum tau graphite nuclei ntau dua, thaum nyias seem yog rhiab heev rau nitrogen ntsig txog porosity, yog li ob qho tib si theem ntxiv thiab qhov loj me me faib tau hloov mus rau qhov casting es tsis yog rau daim ntawv qhia ruaj.
Graphite Nodularity, Chill thiab Carbide Tiv Thaiv
Silicon ua raws li cov khoom siv graphitizing, txhawb cov pa roj carbon monoxide los tsim graphite es tsis txhob sib xyaw carbides, thiab qhov no ncaj qha txhim kho ductility thiab toughness nyob rau hauv lub tiav casting. Nitrogen, tso tawm nyob rau hauv qhov tseeb, txhawb kev nplua thiab sib npaug ntawm cov graphite nodules, cov yam ntxwv ntawm cov hlau uas muab cov hlau txuas nrog lub zog, kev cuam tshuam thiab kev ua haujlwm. Vim hais tias ob qho tib si los txog ua ke, nodularisation ua tau zoo ib yam, txias npoo thiab tawv me ntsis yog suppressed, thiab kev pheej hmoo ntawm carbide tes hauj lwm nyob rau hauv nyias phab ntsa poob ceeb thawj.
Inoculation Practice: Ladle, Hauv -Pwm thiab Late Ntxiv
Ladle inoculation- Ntxiv rau qhov tso rau hauv lub ladle thaum lub sij hawm tapping, muab kev sib cais zoo thiab lub sij hawm teb ntev rau cov ntu nruab nrab thiab hnyav.
Hauv - pwm inoculation- graded particles muab tso rau hauv pwm khiav, xa cov nyhuv nucleating qhov twg cov hlau nkag mus rau hauv kab noj hniav thiab limiting ploj.
Late kwj ntxiv- cov khoom zoo pub rau hauv cov dej ntws rau cov phab ntsa nyias thiab ua haujlwm ntev ntev.
Kev pom zoo ntxiv theem yog teem los ntawm cov foundry los ntawm cov qib sulfur, lub hom phiaj nitrogen, lub pouring kub thiab cov seem modulus. Txawm li cas los xij yog xaiv txoj kev, lub hom phiaj yog tib yam: tau txais cov nucleating hais rau hauv cov hlau tom qab nws tau superheated, thiab ua ntej thawj cov nplej pib khov.
Kev tuav, kev sib raug zoo thiab txheej txheem kev lag luam
FeSiN yog ib qho chaw ruaj khov, yog li ib qho ntxiv tuaj yeem hloov ib feem ntawm cov pa ferrosilicon inoculation thaum tseem muab cov nitrogen xav tau. Qhov kev ua kom yooj yim no txo cov naj npawb ntawm qhov hnyav ntawm lub qhov cub, txo qhov kev ua yuam kev thiab ua rau kev kho mob ntau dua ntawm kev hloov pauv. Cov khoom siv tau muab ntim rau hauv cov ntim ntim ntim ntim thiab yuav tsum tau muab cia kom qhuav; Cov khoom ntub dej tuaj yeem ua kom paub cov hydrogen rau hauv cov yaj, yog li lub hnab qhib sai sai ua ntej siv thiab cov hnab ntim tau rov qab.
Quality Control ntawm Foundry
| Tswj Point | Txoj kev | Txais Kev Pom Zoo |
|---|---|---|
| Cov khoom tuaj | Nitrogen thiab silicon tsom xam, ntsuas qhov loj me | Qib conformity, tsawg nplua, qhuav mob |
| Melt chemistry | Thermal tsom xam thiab spectroscopy | Carbon sib npaug, sulphur, residual magnesium |
| Nodularity | Microsection los ntawm ib tug cast test block | Nodule suav, nodularity, tsis muaj chunky graphite |
| Kev kuaj xyuas tsis raug | Chill wedge test, visual and dye penetrant | Chill qhov tob, carbides, defects nto |
Sau qhov hnyav ntxiv, qhov loj me me thiab qhov kub thiab txias nrog rau qhov tshwm sim nodularity yog txoj hauv kev ceev tshaj plaws los tsim lub qhov rais txheej txheem rau ib qho qauv, thiab nws hloov qhov kev sim inoculation mus rau hauv tus qauv tsim rov ua dua.
Cov lus nug nquag
Q: Yuav ua li cas ferro silicon nitride txhim kho cam khwb cia hlau zoo?
A: Nws tso cov tshuaj silicon thiab nitrogen hauv cov yaj. Silicon txhawb nqa graphite es tsis yog carbide tsim, thiab nitrogen refines lub graphite yog li nodules yog finer, ntau ntau thiab ntau tusyees faib, uas txhim kho lub zog thiab machinability.
Q: Puas yog FeSiN haum rau ob qho tib si ductile thiab grey hlau?
A: Yog. Ductile hlau tau txais nodule refinement thiab txias tswj, thaum grey hlau tau txhim kho graphite tis thiab ntau yam hardness. Cov qib ntxiv sib txawv vim tias ob lub hlau teb txawv rau nitrogen.
Q: Puas yog nitrogen los ntawm FeSiN ua rau porosity?
A: Nitrogen feem ntau tau txais txiaj ntsig zoo ntawm cov qib xa los ntawm nitride inoculant, tab sis ntau ntxiv hauv cov ntu nyias, ceev khov tuaj yeem ua rau muaj roj tsis xws luag. Qhov no yog vim li cas qhov sib ntxiv yog teem los ntawm ntu tuab thiab los ntawm lub hom phiaj nitrogen.
Q: FeSiN puas tuaj yeem hloov cov pa ferrosilicon inoculation tiav?
A: Nyob rau hauv ntau lub foundries nws yog siv nrog ib tug pa inoculant, noj ib feem ntawm lub nucleation lub luag hauj lwm thaum ntxiv nitrogen. Ib qho yooj yim pouring mus sib piv nodularity, txias qhov tob thiab qhov tsis xws luag qhia tau hais tias nyob deb npaum li cas nws tuaj yeem hloov pauv hauv lub khw.
Q: Dab tsi particle loj yuav tsum xaiv?
A: Fine sizes suit streams and in -pwm inoculation where dissolution will be quick, while coarser sizes suit ladle add on heavy castings where a long, slower response is want.
Q: Yuav ua li cas ferro silicon nitride khaws cia?
A: Khaws nws ntim rau hauv cov khoom ntim dej noo hauv lub khw qhuav. Cov khoom ntub dej muaj kev pheej hmoo ntxiv hydrogen rau yaj thiab poob tus cwj pwm tsis pub dawb uas ua rau kev noj tshuaj kom raug.