Lub peev xwm ntawm cov khoom siv hlau kom tawm tsam qhov indentation ntawm saum npoo los ntawm cov khoom tawv yog hu ua hardness. Raws li cov qauv kev xeem sib txawv thiab cov ntawv thov tau muab faib ua brinell hardness, rockers hardness, ntug dej hardness, microhardness thiab kub nyhiab. Muaj peb feem ntau siv hardnesses rau cov kav dej: brinell, rockwell, thiab vickers hardness.
A. Brinell hardness (HB)
Siv cov pob hlau lossis carbide pob ntawm ib qho ib qho uas hla mus rau hauv cov piv txwv saum npoo nrog lub zog ntsuas (f). Tom qab lub sijhawm tuav tseg, tshem tawm cov kev sim quab yuam thiab ntsuas qhov indentation inch (l) ntawm cov qauv saum npoo. Brinell hardness tus nqi yog qhov muaj txiaj ntsig tau los ntawm kev faib cov kev sim los ntawm thaj chaw ntawm lub ntsej muag. Qhia nyob rau hauv HBS (steel pob), chav tsev yog n / mm2 (mpa).
Cov lej suav yog:
Hauv cov qauv: F-qhov kev sim siab yuam nias rau saum npoo ntawm cov qauv hlau, n;
D-txoj kab uas hla ntawm cov pob hlau rau kev kuaj, hli;
d-nruab nrab txoj kab uas hla ntawm indentation, mm.
Kev ntsuas ntawm brinell hardness yog qhov tseeb dua thiab txhim khu kev qha, tab sis feem ntau HBS tsuas yog tsim nyog rau cov hlau tawv lossis cov phiaj thinner. Ntawm cov qauv yeeb nkab steel, brinell hardness yog qhov feem ntau siv. Indentation Inch d feem ntau siv los nthuav tawm qhov tawv tawv ntawm cov khoom, uas yog ob qho tib si intuitive thiab yooj yim.
Piv txwv li: 120HBS10 / 1000130: Nws txhais tau tias Brinell hardnness tus nqi ntsuas los ntawm kev siv 10000kgf (9.807) yog 120n / mm2 (mpa).
B. Rockwell Hardness (HR)
Lub rockwell hardness ntsuas, zoo li brinell hardness ntsuas, yog ib txoj kev ntsuas indentation. Qhov sib txawv yog tias nws ntsuas qhov tob ntawm indentation. Ntawd yog, hauv qab kev ua kab ke ntawm thawj zaug sim quab yuam (FO) Tom qab lub sijhawm tuav tseg, lub zog tseem ceeb tau raug tshem tawm. Kev sim quab yuam, siv cov ntsuas ntsuas seem ntawm qhov tob tob (e) los laij cov nqi tawv. Nws tus nqi yog tus lej tsis qhia npe, sawv cev los ntawm lub cim HR, thiab cov teev, suav nrog A, F, thiab cov teev feem ntau siv rau cov hlau Kev sim ua nyuaj yog ib qho, b, thiab c, uas yog HRA, HRB, thiab HRC.
Lub hardness tus nqi yog xam siv cov qauv hauv qab no:
Thaum kuaj mob nrog A thiab C nplai, HR = 100-E
Thaum kuaj nrog b nplai, hr = 130-e
Hauv cov qauv, E - cov seem ntawm qhov tob tob tau nce qib ntawm 0.002mm, uas yog, thaum lub axial kev hloov yog ib chav (0.002mm), nws yog sib npaug rau kev hloov pauv ntawm rockwell hardness los ntawm ib tug Tus naj npawb. Qhov loj dua tus nqi e qhov loj, qis dua lub hardness ntawm cov hlau, thiab vice versa.
Cov kev ntsuas ntawm cov saum toj no peb teev muaj raws li hauv qab no:
HA (DIAMOND lub khob raj ntawm indenter) 20-88
HRC (Pob Zeb Diamond Lub khob coote indenter) 20-70
HRB (Inch 1.588mm Hlau Pob Indenenter) 20-100
Rockwell Hardness yog ib txoj kev siv dav dav tam sim no, ntawm HRC cov qauv steel hlau tsuas yog brinell hardness HB. Rockwell Hardness tuaj yeem siv los ntsuas cov ntaub ntawv hlau los ntawm cov khoom muag muag muag tsis tshua muaj zog. Nws ua rau qhov tsis muaj peev xwm ntawm Brinell txoj kev. Nws yog qhov yooj yim dua li lub brinell txoj kev thiab lub hardness tus nqi tuaj yeem nyeem ncaj qha los ntawm kev hu xov tooj ntawm lub hardness. Txawm li cas los xij, vim nws cov me me indentation, lub hardness tus nqi tsis yog qhov tseeb yog qhov qauv brinell.
C. Vickers Hardness (HV)
Lub Vickers Hardness Test kuj yog txoj kev ntsuas indentation. Nws nias lub xwmfab pyramidal indenter nrog lub kaum sab xis ntawm 1360 ntawm qhov sib luag ntawm cov quab yuam xaiv (F), thiab tshem nws tom qab lub sijhawm tuav tseg. Yuam kev, ntsuas qhov ntev ntawm ob lub cim ntawm indentation.
Lub Vickers hardness tus nqi yog qhov quotient ntawm kev sim quab yuam faib los ntawm thaj chaw indentation. Nws cov kev suav cov lej yog:
Hauv cov qauv: HV-vickers hardness cim, n / mm2 (mpa);
F-xeem quab yuam, n;
D-lub arithmetic txhais tau li ntawm ob lub cim ntawm indentation, mm.
Kev sim ua f siv hauv vickers hardness yog 5 (49.03), 20 (2090.7) KGF (n) thiab lwm yam rau qib. Tus nqi hardness tuaj yeem ntsuas cov muaj ntau yog 5 ~ 1000hv.
Piv txwv ntawm txoj kev hais tawm: 640Hv30 / 20 txhais tau tias Vickers hardness tus nqi ntsuas nrog kev sim siab ntawm 30hgf (294.2n) yog 640n / mpa).
Lub vickers hardness txoj kev tuaj yeem siv los txiav txim siab lub hardness ntawm cov ntaub ntawv nyias nyias hlau thiab txheej. Nws muaj qhov zoo ntawm brinell thiab rockwell txoj kev thiab kov yeej lawv cov shortcomings, tab sis nws tsis yooj yim li cov txheej txheem rockwell. Vickers txoj kev tsis tshua siv nyob rau hauv cov qauv yeeb nkab steel hlau.
Lub Sijhawm Post: Apr-03-2024