Peb tus qauv hardness rau hlau

Lub peev xwm ntawm cov khoom siv hlau los tiv thaiv qhov nkag ntawm qhov chaw los ntawm cov khoom tawv hu ua qhov nyuaj. Raws li ntau txoj kev sim thiab qhov ntau thiab tsawg ntawm daim ntawv thov, qhov nyuaj tuaj yeem faib ua Brinell hardness, Rockwell hardness, Vickers hardness, Shore hardness, microhardness thiab high temperature hardness. Muaj peb qhov nyuaj uas siv rau cov kav dej: Brinell, Rockwell, thiab Vickers hardness.

A. Brinell hardness (HB)

Siv lub pob hlau lossis lub pob carbide uas muaj ib txoj kab uas hla los nias rau hauv qhov chaw kuaj nrog lub zog kuaj uas tau teev tseg (F). Tom qab lub sijhawm tuav uas tau teev tseg, tshem lub zog kuaj thiab ntsuas qhov txoj kab uas hla ntawm qhov chaw kuaj (L). Tus nqi Brinell hardness yog qhov quotient tau los ntawm kev faib lub zog kuaj los ntawm thaj chaw ntawm lub pob uas tau teev tseg. Qhia hauv HBS (pob hlau), chav tsev yog N/mm2 (MPa).

Cov qauv xam yog:
Hauv cov mis: F - lub zog sim nias rau hauv qhov chaw ntawm cov qauv hlau, N;
D - Txoj kab uas hla ntawm lub pob hlau rau kev sim, mm;
d - qhov nruab nrab txoj kab uas hla ntawm qhov indentation, mm.
Qhov kev ntsuas ntawm Brinell hardness yog qhov tseeb dua thiab txhim khu kev qha, tab sis feem ntau HBS tsuas yog haum rau cov khoom siv hlau hauv qab 450N / mm2 (MPa), thiab tsis haum rau cov hlau tawv dua lossis cov phaj nyias dua. Ntawm cov qauv yeeb nkab hlau, Brinell hardness yog qhov siv dav tshaj plaws. Lub indentation diameter d feem ntau yog siv los qhia qhov nyuaj ntawm cov khoom siv, uas yog ob qho tib si intuitive thiab yooj yim.
Piv txwv li: 120HBS10/1000130: Nws txhais tau tias tus nqi Brinell hardness ntsuas los ntawm kev siv lub pob hlau 10 hli txoj kab uas hla nyob rau hauv lub zog sim ntawm 1000Kgf (9.807KN) rau 30 vib nas this (vij voog) yog 120N / mm2 (MPa).

B. Rockwell hardness (HR)

Kev xeem Rockwell hardness, zoo li kev xeem Brinell hardness, yog ib txoj kev xeem indentation. Qhov txawv yog tias nws ntsuas qhov tob ntawm indentation. Uas yog, nyob rau hauv qhov kev ua ntawm lub zog xeem pib (Fo) thiab tag nrho lub zog xeem (F), lub indenter (cone lossis pob hlau ntawm lub zeb hlau) raug nias rau hauv qhov chaw ntawm cov qauv. Tom qab lub sijhawm tuav tau teev tseg, lub zog tseem ceeb raug tshem tawm. Lub zog xeem, siv qhov ntsuas qhov tob indentation increment (e) los xam qhov nyuaj. Nws tus nqi yog tus lej tsis qhia npe, sawv cev los ntawm lub cim HR, thiab cov nplai siv suav nrog 9 nplai, suav nrog A, B, C, D, E, F, G, H, thiab K. Ntawm lawv, cov nplai feem ntau siv rau kev xeem hlau hardness feem ntau yog A, B, thiab C, uas yog HRA, HRB, thiab HRC.

Tus nqi hardness yog xam los ntawm kev siv cov mis hauv qab no:
Thaum sim nrog A thiab C nplai, HR = 100-e
Thaum sim nrog B scale, HR = 130-e
Hauv cov mis, e - qhov seem indentation tob nce ntxiv yog qhia hauv chav tsev teev tseg ntawm 0.002 hli, uas yog, thaum lub axial displacement ntawm lub indenter yog ib chav tsev (0.002 hli), nws yog sib npaug rau kev hloov pauv hauv Rockwell hardness los ntawm ib tus lej. Qhov loj dua tus nqi e, qhov qis dua qhov nyuaj ntawm cov hlau, thiab vice versa.
Qhov siv tau ntawm peb qhov ntsuas saum toj no yog raws li nram no:
HRA (lub pob zeb diamond cone indenter) 20-88
HRC (lub pob zeb diamond cone indenter) 20-70
HRB (lub taub 1.588 hli hlau pob indenter) 20-100
Kev ntsuas Rockwell hardness yog ib txoj kev siv dav dav tam sim no, ntawm cov uas HRC siv rau hauv cov yeeb nkab hlau tus qauv thib ob tsuas yog Brinell hardness HB. Rockwell hardness tuaj yeem siv los ntsuas cov khoom siv hlau los ntawm qhov mos heev mus rau qhov nyuaj heev. Nws ua rau muaj qhov tsis zoo ntawm txoj kev Brinell. Nws yooj yim dua li txoj kev Brinell thiab tus nqi hardness tuaj yeem nyeem ncaj qha los ntawm lub xov tooj ntawm lub tshuab hardness. Txawm li cas los xij, vim nws qhov me me indentation, tus nqi hardness tsis raug li txoj kev Brinell.

C. Vickers hardness (HV)

Qhov kev xeem Vickers hardness kuj yog ib txoj kev xeem indentation. Nws nias lub square pyramidal diamond indenter nrog lub kaum sab xis ntawm 1360 ntawm cov chaw sib txawv rau hauv qhov chaw xeem ntawm lub zog xeem xaiv (F), thiab tshem nws tawm tom qab lub sijhawm tuav teev tseg. Force, ntsuas qhov ntev ntawm ob lub diagonals ntawm indentation.

Tus nqi Vickers hardness yog qhov sib piv ntawm lub zog sim faib los ntawm thaj chaw ntawm qhov chaw indentation. Nws cov qauv xam yog:
Hauv cov mis: HV-Vickers hardness cim, N/mm2 (MPa);
F–lub zog sim, N;
d - qhov nruab nrab ntawm ob txoj kab pheeb ces kaum ntawm qhov indentation, mm.
Lub zog sim F siv hauv Vickers hardness yog 5 (49.03), 10 (98.07), 20 (196.1), 30 (294.2), 50 (490.3), 100 (980.7) Kgf (N) thiab lwm rau qib. Tus nqi hardness tuaj yeem ntsuas tau Qhov ntau yog 5 ~ 1000HV.
Piv txwv ntawm txoj kev qhia tawm: 640HV30/20 txhais tau tias tus nqi Vickers hardness ntsuas nrog lub zog sim ntawm 30Hgf (294.2N) rau 20S (victorias) yog 640N/mm2 (MPa).
Txoj kev ntsuas Vickers hardness siv tau los txiav txim siab qhov nyuaj ntawm cov khoom siv hlau nyias nyias thiab cov txheej saum npoo. Nws muaj cov txiaj ntsig tseem ceeb ntawm Brinell thiab Rockwell txoj kev thiab kov yeej lawv cov qhov tsis zoo, tab sis nws tsis yooj yim li Rockwell txoj kev. Txoj kev Vickers tsis tshua siv hauv cov qauv yeeb nkab hlau.