Kode y'ubukomere bw'icyuma ni H. Dukurikije uburyo butandukanye bwo gupima ubukomere, ibipimo bisanzwe birimo Brinell (HB), Rockwell (HRC), Vickers (HV), Leeb (HL), ubukomere bwa Shore (HS), nibindi, muri byo HB na HRC bikunze gukoreshwa cyane. HB ifite uburyo bwinshi bwo gukoresha, kandi HRC ikwiriye ibikoresho bifite ubukomere bwinshi bwo hejuru, nko gukomerera mu bushyuhe. Itandukaniro ni uko indenter y'icyuma gipima ubukomere itandukanye. Brinell ipima ubukomere ni indenter y'umupira, mu gihe Rockwell ipima ubukomere ari indenter ya diyama.
HV-ikwiriye gusesengura mikorosikopi. Ubukana bwa Vickers (HV) Kanda ubuso bw'ibikoresho ufite umutwaro uri munsi ya 120kg n'ikirenge cya diyama gifite inguni ya 136°. Ubuso bw'aho ibikoresho bishyirwa bugabanyijemo agaciro k'umutwaro, ari nacyo gipimo cy'ubukana bwa Vickers (HV). Ubukana bwa Vickers bugaragazwa nka HV (reba GB/T4340-1999), kandi bupima ingero nto cyane.
Igipimo cy’ubukana cya HL gikoreshwa mu gupima ubukana cyoroshye. Gikoresha umutwe w’umupira w’ingufu kugira ngo gikore ku buso bw’ubukana kandi gitange umuvuduko. Ubukana bubarwa hakurikijwe igipimo cy’umuvuduko wo gusubira inyuma kw’umuvuduko w’umuvuduko kuri mm 1 uvuye ku buso bw’icyitegererezo kugeza ku muvuduko wo gutera. Ifishi ni: Ubukana bwa Leeb HL = 1000 × VB (umuvuduko wo gusubira inyuma) / VA (umuvuduko w’ingaruka).
Igipimo cy’ubukana bwa Leeb gishobora guhindurwamo ubukana bwa Brinell (HB), Rockwell (HRC), Vickers (HV), Shore (HS) nyuma yo gupima Leeb (HL). Cyangwa ukoreshe ihame rya Leeb kugira ngo upime neza agaciro k’ubukana ukoresheje Brinell (HB), Rockwell (HRC), Vickers (HV), Leeb (HL), Shore (HS).
Ubukomere bwa HB - Brinell:
Ubukana bwa Brinell (HB) bukoreshwa muri rusange iyo ibikoresho byoroshye, nk'ibyuma bidafite feri, icyuma mbere yo kugitunganya cyangwa nyuma yo kugishyiraho. Ubukana bwa Rockwell (HRC) bukoreshwa muri rusange ku bikoresho bifite ubukana bwinshi, nko ubukana nyuma yo kugitunganya, nibindi.
Ubukana bwa Brinell (HB) ni umutwaro w'igerageza ufite ingano runaka. Umupira w'icyuma gikomeye cyangwa umupira wa karubide ufite umurambararo runaka ushyirwa ku buso bw'icyuma kugira ngo upimwe. Umutwaro w'igerageza ugumaho igihe runaka, hanyuma umutwaro ugakurwaho kugira ngo hapimwe umurambararo w'umubyimba uri ku buso bugomba kugeragezwa. Agaciro k'ubukana bwa Brinell ni quotient iboneka mu kugabanya umutwaro n'ubuso bw'uruziga bw'umubyimba. Muri rusange, umupira w'icyuma ukomeye ufite ingano runaka (ubusanzwe 10mm mu murambararo) ushyirwa ku buso bw'ibikoresho hamwe n'umutwaro runaka (ubusanzwe 3000kg) kandi ugakomeza igihe runaka. Nyuma yo gukuraho umutwaro, igipimo cy'umutwaro n'agace k'umubyimba ni agaciro k'ubukana bwa Brinell (HB), kandi igice ni kilogarama imbaraga / mm2 (N / mm2).
Ubukana bwa Rockwell bugena agaciro k'ubukana bushingiye ku burebure bwa pulasitiki bwo guhindagurika kw'aho ikintu gishyirwa. 0.002 mm ikoreshwa nk'igice cy'ubukana. Iyo HB>450 cyangwa icyitegererezo ari gito cyane, ikizamini cy'ubukana cya Brinell ntigishobora gukoreshwa kandi hakoreshwa igipimo cy'ubukana bwa Rockwell. Gikoresha agace ka diyama gafite inguni ya 120° cyangwa umupira w'icyuma ufite umurambararo wa 1.59 cyangwa 3.18mm kugira ngo gitere hejuru y'ikintu kiri mu igeragezwa munsi y'umutwaro runaka, kandi ubukana bw'ikintu bubarwa uhereye ku bujyakuzimu bw'aho ikintu gishyirwa. Dukurikije ubukana bw'ibikoresho bipimwa, bigaragazwa mu bipimo bitatu bitandukanye:
HRA: Ni ubukana buboneka hakoreshejwe umutwaro wa kilogarama 60 hamwe n'icyuma gikingira diyama, gikoreshwa mu bikoresho bifite ubukana bwinshi cyane (nk'ikarubide ikozwe muri sima, nibindi).
HRB: Ni ubukana buboneka hakoreshejwe umutwaro wa kilogarama 100 n'umupira w'icyuma ukomeye ufite umurambararo wa mm 1.58, ukoreshwa ku bikoresho bifite ubukana buke (nk'icyuma gishongeshejwe, icyuma gishongeshejwe, nibindi).
HRC: Ni ubukana buboneka hakoreshejwe umutwaro wa kilogarama 150 hamwe n'icyuma gikingira diyama, gikoreshwa mu bikoresho bifite ubukana bwinshi cyane (nk'icyuma gikomeye, nibindi).
Byongeye kandi:
1.HRC bivuze igipimo cya Rockwell cy'ubukana bwa C.
2.HRC na HB bikoreshwa cyane mu gukora.
3. HRC ikoreshwa HRC 20-67, ingana na HB225-650,
Niba ubukana buri hejuru y'ubu bwoko, koresha Rockwell hardness A scale HRA,
Niba ubukana buri hasi ugereranije n'ubu bwoko, koresha Rockwell hardness scale B HRB,
Uruhare rwo hejuru rw'ubukomere bwa Brinell ni HB650, rudashobora kuba hejuru y'iki gipimo.
4. Ingano y'icyuma gipima ubukana bwa Rockwell C ni agace ka diyama gafite inguni ya dogere 120. Umutwaro w'ikizamini ufite agaciro runaka. Igipimo cy'Abashinwa ni 150 kgf. Ingano y'icyuma gipima ubukana cya Brinell ni umupira w'icyuma gikonje (HBS) cyangwa umupira wa karubide (HBW). Umutwaro w'ikizamini uratandukanye bitewe n'umurambararo w'umupira, kuva kuri 3000 kugeza 31.25 kgf.
5. Icyiciro cyo gukomeretsa cya Rockwell ni gito cyane, kandi agaciro kapimwe kari ahantu runaka. Ni ngombwa gupima ingingo nyinshi kugira ngo ubone agaciro mpuzandengo. Kirakwiriye ku bicuruzwa byarangiye n'ibice bito kandi gishyirwa mu cyiciro cyo gupima kitangiza. Icyiciro cyo gukomeretsa cya Brinell ni kinini, agaciro kapimwe ni ko gakwiye, ntikibereye ku bicuruzwa byarangiye n'ibice bito, kandi muri rusange ntikibarizwa mu cyiciro cyo gupima kitangiza.
6. Agaciro k'ubukana bwa Rockwell ni umubare utazwi udafite ibipimo. (Kubera iyo mpamvu, si byiza kwita ubukana bwa Rockwell nk'urugero runaka.) Agaciro k'ubukana bwa Brinell gafite ibipimo kandi gafite isano runaka n'imbaraga zo gukurura.
7. Ubukana bwa Rockwell bugaragara neza kuri dial cyangwa bugaragara mu buryo bw'ikoranabuhanga. Byoroshye gukoresha, byihuse kandi byoroshye gukoresha, kandi birakwiriye gukora ibintu byinshi. Ubukana bwa Brinell busaba mikorosikopi kugira ngo ipime umurambararo w'inyuma, hanyuma irebe mu mbonerahamwe cyangwa ibarwe, ibyo bikaba bigoye cyane kuyikoresha.
8. Mu bihe bimwe na bimwe, HB na HRC bishobora guhindurwa urebye imbonerahamwe. Inzira yo kubara mu mutwe ishobora kwandikwa mu buryo burambuye nka: 1HRC≈1/10HB.
Ikizamini cy'ubukomere ni uburyo bworoshye kandi bworoshye bwo gupima mu ikizamini cy'imiterere y'imashini. Kugira ngo ikizamini cy'ubukomere gikoreshwe mu gusimbuza ibizamini bimwe na bimwe by'imiterere y'imashini, hakenewe isano nyayo hagati y'ubukomere n'imbaraga mu gukora.
Imyitozo yagaragaje ko hari isano iri hagati y’agaciro gatandukanye k’ubukomere bw’ibikoresho by’icyuma no hagati y’agaciro k’ubukomere n’agaciro k’imbaraga. Kubera ko agaciro k’ubukomere kagenwa n’ubudahangarwa bwa mbere bwo kwangirika kwa pulasitiki no gukomeza kwangirika kwa pulasitiki, uko imbaraga z’ibikoresho ziyongera, ni ko ubudahangarwa bwa pulasitiki burushaho kwiyongera, kandi ubudahangarwa burushaho kwiyongera.
Igihe cyo kohereza: Kanama-16-2024
