Amandla ezinto zesinyithi okumelana nokubotshwa komphezulu zizinto eziqinileyo abizwa ngokuba bubunzima. Ngokweendlela ezahlukeneyo zovavanyo kunye nobubanzi bokusetyenziswa, ubulukhuni bunokwahlulwahlulwa bube bubunzima beBrinell, ubunzima beRockwell, ubunzima beVickers, ubunzima beShore, ubunzima obuncinci kunye nobunzima obuphezulu bobushushu. Kukho ubunzima obuthathu obusetyenziswa rhoqo kwiipayipi: ubunzima beBrinell, Rockwell, kunye nobunzima beVickers.
A. Ubunzima bukaBrinell (HB)
Sebenzisa ibhola yentsimbi okanye ibhola yekhabhayithi enobubanzi obuthile ukuze ucinezele kumphezulu wesampuli ngamandla ovavanyo acacisiweyo (F). Emva kwexesha elichaziweyo lokubamba, susa amandla ovavanyo uze ulinganise ububanzi bokutsalwa (L) kumphezulu wesampuli. Ixabiso lobunzima beBrinell yi-quotient efunyenwe ngokwahlula amandla ovavanyo ngendawo yomphezulu we-indented sphere. Ichazwa kwi-HBS (ibhola yentsimbi), iyunithi yi-N/mm2 (MPa).
Ifomula yokubala yile:
Kwifomyula: F–amandla ovavanyo acinezelwe kumphezulu wesampuli yesinyithi, N;
Ububanzi bebhola yentsimbi ye-D yovavanyo, mm;
d–ububanzi obuphakathi bokutsalwa, mm.
Ukulinganiswa kobulukhuni beBrinell kuchanekile kwaye kuthembekile, kodwa ngokubanzi i-HBS ifanelekile kuphela kwizixhobo zesinyithi ezingaphantsi kwe-450N/mm2 (MPa), kwaye ayifanelekanga kwintsimbi eqinileyo okanye kwiipleyiti ezincinci. Phakathi kwemigangatho yemibhobho yentsimbi, ubulukhuni beBrinell bobona busetyenziswa kakhulu. Ububanzi bokutsalwa kwe-indentation d budla ngokusetyenziswa ukubonisa ubulukhuni bezinto, obuqondakala lula kwaye bulula.
Umzekelo: 120HBS10/1000130: Kuthetha ukuba ixabiso lobunzima beBrinell elilinganiswa ngokusebenzisa ibhola yentsimbi enobubanzi obuyi-10mm phantsi kwamandla ovavanyo e-1000Kgf (9.807KN) kangangemizuzwana engama-30 (imizuzwana) yi-120N/mm2 (MPa).
B. Ubunzima beRockwell (HR)
Uvavanyo lokuqina kweRockwell, njengovavanyo lokuqina kweBrinell, yindlela yovavanyo lokugoba. Umahluko kukuba lulinganisa ubunzulu bokugoba. Oko kukuthi, phantsi kwesenzo esilandelelanayo samandla okuqala ovavanyo (Fo) kunye namandla ovavanyo apheleleyo (F), i-indenter (ikhowuni okanye ibhola yentsimbi yesixhobo sokugaya intsimbi) icinezelwa kumphezulu wesampuli. Emva kwexesha elichaziweyo lokubamba, amandla aphambili ayasuswa. Amandla ovavanyo, sebenzisa i-residual indentation depth increment (e) elinganisiweyo ukuze ubale ixabiso lokuqina. Ixabiso layo linani elingaziwayo, elimelwe luphawu lwe-HR, kwaye izikali ezisetyenzisiweyo ziquka izikali ezili-9, kuquka u-A, B, C, D, E, F, G, H, kunye no-K. Phakathi kwazo, izikali ezisetyenziswa rhoqo kuvavanyo lokuqina kwentsimbi ngokubanzi yi-A, B, kunye no-C, oko kukuthi i-HRA, HRB, kunye ne-HRC.
Ixabiso lobunzima libalwa kusetyenziswa le fomyula ilandelayo:
Xa uvavanya ngezikali ze-A kunye ne-C, i-HR=100-e
Xa uvavanya ngesikali se-B, i-HR=130-e
Kwifomula, i-e – ukunyuka kobunzulu bokutsalela okushiyekileyo kubonakaliswa kwiyunithi echaziweyo ye-0.002mm, oko kukuthi, xa ukufuduka kwe-axial ye-indenter kuyiyunithi enye (0.002mm), ilingana notshintsho kubunzima beRockwell ngenani elinye. Okukhona ixabiso le-e lilikhulu, kokukhona ubunzima besinyithi buphantsi, kwaye ngokuchaseneyo.
Ububanzi obufanelekileyo bezikali ezintathu zingasentla bulandelayo:
I-HRA (i-indenter yekhowuni yedayimani) 20-88
I-HRC (i-indenter yekhowuni yedayimani) 20-70
I-HRB (ububanzi be-1.588mm yentsimbi endenter yebhola) 20-100
Uvavanyo lokuqina kweRockwell yindlela esetyenziswa kakhulu okwangoku, apho i-HRC isetyenziswa kwimigangatho yemibhobho yentsimbi, yesibini emva kweBrinell hardness HB. Ukuqina kweRockwell kungasetyenziselwa ukulinganisa izinto zesinyithi ukusuka ekuthambileyo kakhulu ukuya ekuqineni kakhulu. Ilungisa iintsilelo zendlela yeBrinell. Ilula kunendlela yeBrinell kwaye ixabiso lokuqina linokufundwa ngokuthe ngqo kwi-dial yomatshini wokuqina. Nangona kunjalo, ngenxa yokuxinana kwayo okuncinci, ixabiso lokuqina alichanekanga njengendlela yeBrinell.
C. Ubulukhuni beVickers (HV)
Uvavanyo lobunzima beVickers lukwayindlela yovavanyo lokugoba. Lucinezela i-indenter yesikwere se-pyramidal diamond ene-engile ebandakanyiweyo ye-1360 phakathi kweendawo ezichaseneyo kumphezulu wovavanyo kumandla ovavanyo akhethiweyo (F), kwaye luyisuse emva kwexesha elichaziweyo lokubamba. Cinezela, linganisa ubude bee-diagonals ezimbini ze-indent.
Ixabiso lobunzima beVickers yi-quotient yamandla ovavanyo ahlulwe ngendawo yomphezulu we-indentation. Ifomula yayo yokubala yile:
Kwifomyula: Uphawu lobunzima be-HV–Vickers, N/mm2 (MPa);
Amandla ovavanyo lwe-F, N;
d–i-avareji yezibalo zee-diagonals ezimbini ze-indentation, mm.
Amandla ovavanyo u-F asetyenziswa kwi-Vickers hardness yi-5 (49.03), 10 (98.07), 20 (196.1), 30 (294.2), 50 (490.3), 100 (980.7) Kgf (N) kunye namanye amanqanaba amathandathu. Ixabiso lobunzima linokulinganiswa. Uluhlu luyi-5 ~ 1000HV.
Umzekelo wendlela yokubonakalisa: 640HV30/20 ithetha ukuba ixabiso lobunzima beVickers elilinganiswe ngamandla ovavanyo angama-30Hgf (294.2N) kwi-20S (imizuzwana) yi-640N/mm2 (MPa).
Indlela yokuqina kweVickers ingasetyenziselwa ukufumanisa ubunzima bezinto zesinyithi ezibhityileyo kakhulu kunye neengqimba zomphezulu. Ineenzuzo eziphambili zeendlela zeBrinell kunye neRockwell kwaye iyoyisa iintsilelo zazo ezisisiseko, kodwa ayilula njengendlela yeRockwell. Indlela yeVickers ayisetyenziswa rhoqo kwimigangatho yemibhobho yentsimbi.
Ixesha lokuthumela: Epreli-03-2024
