Radiographic Inspection ntawm Castings

Radiographic Inspection ntawm Castings

 

1. Lub hauv paus ntsiab lus ntawm radiography

Nyob rau hauv tus txheej txheem ntawm kev nkag mus rau lub casting, X-ray los yog γ-ray cuam tshuam nrog cov khoom, thiab nws siv yog attenuated los ntawm kev nqus thiab tawg. Cov duab nrog ntau qhov sib txawv ntawm cov xim dub sib xws rau cov qauv sab hauv thiab qhov tsis xws ntawm cov khoom tuaj yeem tau txais ntawm cov duab thaij duab. Qhov xwm txheej ntawm qhov tsis xws luag yog txiav txim los ntawm yam xws li cov duab, qhov ntau, qhov loj me, kev taw qhia, kev faib tawm thiab qhov dub ntawm daim duab, thiab tom qab ntawd qhov tsis xws luag yog cais thiab ntsuas raws li qhov xwm txheej, qhov loj thiab qhov ntau ntawm qhov tsis xws luag. Nyob rau hauv txoj kev no, peb tuaj yeem paub hom thiab qhov hnyav ntawm qhov tsis xws luag sab hauv ntawm lub casting.

 

2. Radiographic Sensitivity thiab duab zoo

Radiographic rhiab heev yog hais txog lub peev xwm los nrhiav qhov tsis xws luag tsawg tshaj plaws hauv qhov casting. Vim yog qhov cuam tshuam ntawm qhov xwm txheej, qhov chaw, kev taw qhia, qhov ntau, qhov loj thiab lwm yam ntawm qhov tsis xws luag hauv qhov casting, qhov tsis zoo ntawm qhov kev tshawb nrhiav qhov rhiab heev thaum lub sijhawm yees duab yog txiav txim siab los ntawm qhov zoo ntawm cov duab duab. Ib qho duab zoo ntsuas (lwm lub npe hu ua penetrometer) yog qhov taw qhia. Nws yog ua los ntawm tib cov khoom nrog tib lub attenuation coefficient raws li cov casting. Cov duab zoo ntsuas cov duab zoo yog cov hlau-hom duab zoo ntsuas, qhov hom duab zoo ntsuas thiab cov duab hom duab zoo ntsuas. Cov kab (qhov, zawj) txoj kab uas hla ntawm cov duab zoo meter yog sawv cev los ntawm cov duab zoo Performance index. Qhov loj dua qhov ntsuas tus nqi, qhov ua rau cov duab tsis zoo. Nyob rau hauv txoj kev no, radiographic flaw detection rhiab heev tuaj yeem qhia ncaj qha los ntawm cov duab zoo index. Ib qho duab zoo meter yog ib qho cuab yeej los ntsuas qhov zoo ntawm daim duab, nws tsis sawv cev qhov tseeb qhov loj ntawm qhov tsis xws luag hauv qhov casting uas tuaj yeem kuaj pom.

 

3. Feem ntau siv thoob ntiaj teb cov qauv rau kev kuaj hluav taws xob.

ASTM siv hluav taws xob zaj duab xis yog tam sim no thoob ntiaj teb lees paub tus qauv.

 

4. Cov yam ntxwv ntawm Kev Tshawb Fawb Hluav Taws Xob

1) Qhov txiaj ntsig loj tshaj plaws ntawm kev tshuaj xyuas hluav taws xob yog tias nws yog qhov nkag siab thiab yooj yim los txiav txim qhov xwm txheej ntawm qhov tsis xws luag. Internal defects nyob rau hauv castings yuav pom nyob rau hauv zaj duab xis tsuav yog lawv nyob rau hauv cov kev yees duab rhiab heev ntau yam.

2) Kev tshuaj xyuas hluav taws xob muaj qhov ntsuas siab siab rau qhov tsis xws luag (xws li pores, shrinkage kab noj hniav, shrinkage porosity, xuab zeb inclusion, thiab slag inclusion); nws muaj qee qhov rhiab heev rau qhov tsis xws luag (xws li tawg, tsis muaj fusion, thiab lwm yam). Txawm li cas los xij, thaum lub thickness ntawm lub casting yog ntau tshaj 40mm, nws yog ib qho nyuaj rau nrhiav tau qhov loj-chaw shrinkage-zoo li tsis xws luag nyob rau hauv lub radiographic tshuaj ntsuam, thiab nrhiav kom tau rhiab heev ntawm micro-cracks yog tsawg.

3) Cov duab tuaj yeem khaws cia thiab khaws cia ntev ntev rau kev siv tom qab thiab rov kuaj xyuas dua.

4) Radiographic tshuaj xyuas yuav tsum muaj cov cuab yeej tshwj xeeb thiab qhov chaw, tus nqi yog siab, thiab kev tshuaj xyuas lub voj voog ntev, uas tsis haum rau kev soj ntsuam ceev thiab batch ntawm castings.

 

5 Kev faib tawm tsis zoo thiab qib

Lub macroscopic internal defects ntawm castings pom los ntawm radiographic tshuaj ntsuam yuav muab faib ua tsib pawg: porosity, xuab zeb inclusion thiab slag inclusion, shrinkage kab noj hniav thiab shrinkage porosity, unfused puab hlau thiab unfused core, kub tawg thiab txias tawg.

1) Stomal defects. Stomata tshwm raws li puag ncig lossis oval tsaus me ntsis, qee zaum nrog cov tails, faib ua pawg lossis hu nkauj. Thaum muab faib ua pawg, cov duab zoo li sib tshooj thiab muaj cov duab tsis sib xws. Blowholes feem ntau tshwm sim nyob rau hauv qhov kawg solidification ntawm lub casting, qhov twg cov roj sau thiab khiav tsis tau. Kev tsim ntawm rab koob zoo li pores belongs rau hom reactive intrusion, thiab txheej txheej ntawm casting yog teem rau hauv kab thiab dispersedly faib perpendicular rau saum npoo.

2) Qhov tsis xws luag ntawm cov xuab zeb suav nrog thiab slag suav nrog. Xuab zeb thiab slag suav nrog yog muab faib rau hauv qhov chaw tsis xwm yeem lossis kab duab. Thaum lawv nyob hauv kab, lawv muaj qhov dav dav thiab tuaj yeem muab faib ua ntu ntu hauv qhov casting. Slag suav nrog feem ntau tshwm sim nyob ib puag ncig hauv qab ntawm cov kab noj hniav shrinkage, thiab cov xuab zeb suav nrog qee zaum faib rau saum npoo ntawm qhov casting.

3) Shrinkage kab noj hniav thiab shrinkage porosity defects. Raws li peb-dimensional duab, lub shrinkage kab noj hniav defects ntawm castings yuav muab faib ua tubular, dendritic thiab loj-qhov chaw shrinkage kab noj hniav. Xws li qhov tsis xws luag yog feem ntau faib rau hauv qab ntawm riser thiab ntawm qhov kawg solidified kub node. Shrinkage kab noj hniav feem ntau tshwm sim nyob rau tib lub sij hawm xws li pores, slag inclusions thiab shrinkage porosity.

4) Tsis muaj qhov tsis xws luag. Cov duab ntawm qhov tsis xws luag yog zoo ib yam li cov kab nrib pleb, thiab lawv tag nrho cov kab tsaus nti, tab sis ib sab ntawm cov kab yog ib txoj kab ncaj nraim, uas tsuas yog tshwm sim ntawm qhov chaw uas lub chiller sab hauv los yog kev txhawb nqa tseem ceeb.

5) Crack-zoo li tsis xws luag. Hauv kev tshuaj ntsuam xyuas hluav taws xob, cov kab nrib pleb zoo li pom cov kab tsaus nti ntawm daim duab nrog cov duab tsis zoo, qee qhov ncaj, qee qhov yog ncaj, tab sis lawv qhov kawg yog ntse thiab lub taub hau tsis puag ncig. Crack-zoo li qhov tsis xws luag feem ntau tshwm sim ntawm qhov kub ntawm qhov casting lossis kev sib tshuam ntawm kev hloov pauv sai hauv ntu.