Impact toughness ntawm cov ntaub ntawv hlau yog hais txog lawv lub peev xwm los tiv thaiv kev puas tsuaj thiab rov qab deformation thaum raug cuam tshuam rau kev thauj khoom, thiab qhov ntsuas kev ua tau zoo no tseem ceeb heev rau kev siv cov khoom siv. Kev cuam tshuam toughness tsis tsuas yog qhia txog qib ntawm toughness thiab brittleness ntawm cov khoom, tab sis kuj txiav txim siab lub durability thiab kev ntseeg siab ntawm cov khoom nyob rau hauv dynamic load. Muaj ntau yam cuam tshuam rau qhov cuam tshuam qhov hnyav ntawm cov khoom siv hlau, suav nrog qhov xwm txheej ntawm cov khoom siv raw nws tus kheej, kev taw qhia ntawm cov qauv, qhov ntsuas geometry thiab kev ua haujlwm zoo, qhov tseeb ntawm lub tshuab ntsuas, qhov haum ntawm lub pendulum thiab tus ncej, qhov ntsuas kub, qhov chaw ntawm qhov cuam tshuam cov qauv thiab lwm yam.
1. Qhov xwm ntawm cov khoom siv raw nws tus kheej
Qhov cuam tshuam toughness ntawm cov ntaub ntawv hlau yog ze ze rau lawv tus kheej metallographic qauv, tshuaj muaj pes tsawg leeg, lub cev muaj zog, kev ua thiab kev kho cua sov. Piv txwv li, cov tshuaj muaj pes tsawg leeg ntawm cov hlau, tshwj xeeb tshaj yog cov pa roj carbon (C), phosphorus (P), sulfur (S) thiab lwm yam khoom, thaum lawv cov ntsiab lus nce, feem ntau ua rau txo qhov cuam tshuam ntawm cov khoom. Qhov no yog vim hais tias cov ntsiab lus no zoo li tsim cov theem nkig los yog kev koom ua ke hauv cov khoom, ua rau muaj kev ntxhov siab ntau ntxiv thiab txo qhov toughness ntawm cov khoom. Ntawm qhov tsis sib xws, cov ntsiab lus xws li manganese (Mn) thiab npib tsib xee (Ni) tuaj yeem txhim kho qhov tawv tawv ntawm cov khoom hauv qee yam; Mn tuaj yeem ua kom zoo dua cov nplej thiab inhibit qhov nag lossis daus ntawm carbides raws cov ciam teb nplej, thaum Ni tuaj yeem ua kom cov txheej txheej ntawm ferrite thiab txhawb nqa cov hlais hlais ntawm cov khoom tawg, uas tuaj yeem pab txhim kho cov tawv tawv ntawm cov hlau.
Tsis tas li ntawd, cov theem muaj pes tsawg leeg ntawm cov khoom siv hlau kuj tseem muaj txiaj ntsig zoo rau nws qhov toughness. Qhov siab dua cov ntsiab lus ntawm ferrite, ib theem uas tsis muaj zog, zoo plasticity thiab toughness, qhov zoo dua qhov cuam tshuam toughness ntawm cov khoom feem ntau yog. Ntawm qhov tsis sib xws, reticulated carburites deteriorate lub toughness ntawm cov khoom, thiab lawv cov nyiaj ntau dua, qhov cuam tshuam qhov hnyav ntawm cov khoom. Yog li ntawd, los ntawm kev kho cov tshuaj muaj pes tsawg leeg ntawm cov khoom thiab cov txheej txheem kev kho cua sov, cov theem muaj pes tsawg leeg tuaj yeem tswj tau thiab yog li qhov cuam tshuam toughness ntawm cov khoom tuaj yeem ua kom zoo dua.
2. Kev taw qhia ntawm cov qauv
Kev taw qhia ntawm cov khoom siv hlau cuam tshuam rau lawv cov khoom siv kho tshuab, suav nrog toughness. Nyob rau hauv qhov tseeb ntau lawm thiab engineering daim ntaub ntawv, feem ntau ntawm cov ntaub ntawv hlau yog dov, nyob rau hauv lub dov txheej txheem hlau inclusions nrog hlau nplej raws lub ntsiab deformation kev taw qhia yog elongated, tsim ntawm hlau fiber ntaub so ntswg, heev cuam tshuam rau tej yam toughness ntawm cov ntaub ntawv hlau. Yog li ntawd, raws li cov kev taw qhia rolling sampling, uas yog, qhov ntev axis ntawm cov qauv mus rau lub dov kev taw qhia, notch qhib nyob rau hauv cov kev taw qhia perpendicular mus rau lub dov kev taw qhia, thiaj li hais tias qhov cuam tshuam toughness ntawm cov qauv tau los ntawm qhov loj; ntawm qhov tsis sib xws, perpendicular mus rau qhov kev taw qhia dov sampling, raws li qhov kev taw qhia dov ntawm qhov qhib qhov ntsuas, qhov cuam tshuam toughness tau los ntawm cov qauv ntawm qhov me me.
3. Notch geometry thiab kev ua haujlwm zoo
Notch geometry thiab kev ua haujlwm zoo muaj qhov cuam tshuam tseem ceeb ntawm kev cuam tshuam toughness ntawm cov khoom. Raws li GB / T 229-2007 tus qauv, qhov ntsuas qhov ntsuas feem ntau muab faib ua U-hom thiab V-hom ob hom V-hom thais piv rau U-hom thais, qhov kev ntxhov siab ntau dua, yog li nws qhov cuam tshuam toughness yog feem ntau qis dua. Rau tib cov khoom siv hlau, qhov cuam tshuam ntawm cov khoom tsis sib xws yog me dua li cov qauv uas tsis tau sau tseg, vim tias qhov thais yuav ua rau muaj kev ntxhov siab, uas yuav txo qhov toughness ntawm cov khoom. Cov kev cuam tshuam cov qauv muaj qhov tseem ceeb ntawm kev ntxhov siab nyob rau hauv qhov kev txiav txim ntawm I-type, V-type, U-type, thiab semi-circular impact specimens.
Tsis tas li ntawd, kev ua haujlwm tsis zoo kuj yog ib qho tseem ceeb uas cuam tshuam rau kev cuam tshuam toughness. Kev ua haujlwm tsis zoo feem ntau los ntawm kev cuam tshuam ntawm qhov chaw nyob ze ntawm qhov kev ntxhov siab, lim concentration kom cuam tshuam rau qhov cuam tshuam toughness ntawm cov khoom. Cov kev tshawb fawb tau pom tias qhov cuam tshuam toughness ntawm qhov cuam tshuam cov qauv ntsuas qhov tob nrog qhov nce ntawm qhov maj mam txo, nrog rau cov hauv paus hauv paus radius nce, qhov cuam tshuam toughness ntawm cov ntaub ntawv hlau maj mam nce; cuam tshuam toughness nrog rau hauv qab ntawm qhov thais machining khawb, hardening degree ntawm maj mam txo. Yog li ntawd, yuav tsum nruj raws li GB/T 229-2007 cuam tshuam qhov ntsuas qhov ntsuas qhov ntsuas qhov loj ntawm cov kev cai ntawm qhov cuam tshuam cov qauv ua.
4. Qhov tseeb ntawm lub tshuab kuaj thiab lub pendulum thiab ncej nrog kev sib koom tes
Impact toughness ntawm cov ntaub ntawv hlau ntawm qhov cuam tshuam kev kuaj tshuab precision muaj qee yam yuav tsum tau ua, tsis tshua muaj precision kuaj tshuab ntawm qhov cuam tshuam toughness ntawm ntau dua. Tsis tas li ntawd, qhov cuam tshuam toughness kuj muaj feem xyuam rau qhov kev ua yuam kev ntawm qhov cuam tshuam kev ntsuas lub tshuab nyeem ntawv, yog li qhov kev sim yuav tsum tau ua ua ntej xoom ua haujlwm.
Pendulum nrog tus ncej kuj tseem ceeb heev. Kev ntsuam xyuas kev cuam tshuam yog kev sim kev puas tsuaj ib zaug, yog li qhov haum ntawm lub pendulum rau lub thav duab yuav tsum yog qhov tseeb. Qhov no suav nrog parallelism ntawm lub pendulum axis thiab lub dav hlau siv, qhov sib luag ntawm lub pendulum sab thiab lub dav hlau viav vias, radial thiab axial clearance ntawm lub pendulum axis, qhov kev ncua deb ntawm lub pendulum axis mus rau qhov chaw tawm tsam, qhov chaw txheeb ze ntawm lub pendulum axis. cuam tshuam riam ntug thiab kev txhawb nqa ncua, thiab lwm yam, uas yuav tsum ua kom tau raws li cov cai ntawm cov qauv tsim nyog. Thaum tus txheeb ze txoj hauj lwm ntawm qhov cuam tshuam riam ntug thiab qhov kev txhawb nqa qhov nruab nrab tsis ua raws li qhov yuav tsum tau ua, qhov cuam tshuam riam ntug thiab cov qauv thais qhov chaw kab tsis tuaj yeem sib koom ua ke, ua rau qhov ntsuas tsis raug, qhov cuam tshuam toughness yuav loj.
5. Kev ntsuas kub
Kev ntsuas kub kuj yog ib qho tseem ceeb cuam tshuam rau kev cuam tshuam toughness ntawm cov ntaub ntawv. Nyob rau hauv cov txheej txheem kev ntsuam xyuas toughness, kom pom cov khoom nyob rau hauv lub brittle cheeb tsam kub ntau yam, nyob rau hauv kev siv ntawm cov txheej txheem yuav tswj kom tsis txhob lub brittle cheeb tsam kub ntawm cov khoom. Cov ntaub ntawv uas tsis yog-ferrous hlau sib txawv thiab lawv cov kev cuam tshuam toughness los ntawm qhov cuam tshuam ntawm qhov kub thiab txias yog qhov sib txawv, tab sis qhov cuam tshuam rau kev ua haujlwm yog cuam tshuam rau qhov kub ntawm qhov kub, qhov kub thiab txias uniformity, lub sij hawm rwb thaiv tsev ntev. Raws li qhov kub thiab txias, qhov cuam tshuam toughness ntawm cov khoom feem ntau txo qis, qhov no yog vim tias cov yas deformation muaj peev xwm ntawm cov khoom ntawm qhov kub thiab txias yog txo, qhov tawg expansion tus nqi yog ceev, uas ua rau kom ib tug txo nyob rau hauv toughness.
6. Qhov chaw ntawm cov qauv cuam tshuam
Qhov chaw ntawm qhov cuam tshuam cov qauv yog los xyuas kom meej tias cov kab nruab nrab ntawm qhov cuam tshuam cov qauv notch coincides nrog rau ntawm ntug ntawm qhov cuam tshuam riam ntawm lub pendulum kom txo qhov kev ua haujlwm yuam kev. Yog hais tias lawv cov txheeb ze txoj hauj lwm tsis coincide, tsis tuaj yeem ua tau raws li qhov yuav tsum tau ua ntawm 0.5mm, qhov siab tshaj plaws cuam tshuam quab yuam tsis tuaj yeem ua rau qhov cuam tshuam cov qauv txiav tawm qhov tsawg kawg nkaus hla ntu, thaum kawg ua rau qhov cuam tshuam toughness bias.
7. Lwm yam
Ntxiv nrog rau cov xwm txheej saum toj no, qhov tsis xws luag sab hauv thiab impurities ntawm cov ntaub ntawv hlau kuj tseem tuaj yeem cuam tshuam rau lawv cov kev cuam tshuam toughness. Cov tsis xws luag thiab impurities nce kev ntxhov siab concentration thiab txo qhov toughness ntawm cov khoom. Piv txwv li, cov teeb meem sab hauv xws li suav nrog thiab npuas tuaj yeem ua rau tawg pib thiab txuas ntxiv, yog li txo qhov cuam tshuam ntawm cov khoom siv. Txhawm rau txo qhov cuam tshuam ntawm qhov tsis xws luag thiab impurities ntawm qhov toughness ntawm cov ntaub ntawv, qhov zoo ntawm raw cov ntaub ntawv thiab cov xwm txheej ntawm cov txheej txheem ntau lawm yuav tsum tau tswj nruj me ntsis thaum lub sij hawm npaj thiab ua cov ntaub ntawv.
