Ko te kaha o te rauemi whakarewa ki te ātete i te kōpiko o te mata e ngā mea pakeke ka kiia he pakeke. E ai ki ngā tikanga whakamātautau me te whānuitanga o te whakamahinga, ka taea te wehewehe i te pakeke ki te pakeke Brinell, te pakeke Rockwell, te pakeke Vickers, te pakeke Shore, te pakeke moroiti me te pakeke pāmahana teitei. E toru ngā pakeke e whakamahia whānuitia ana mō ngā paipa: te pakeke Brinell, Rockwell, me Vickers.
A. Te pakeketanga o Brinell (HB)
Whakamahia he pōro maitai, he pōro karāhe rānei o tētahi diameter kua tohua hei pēhi ki te mata tauira me te kaha whakamātautau kua tohua (F). I muri i te wā pupuri kua tohua, tangohia te kaha whakamātautau ka ine i te diameter kōpiko (L) i runga i te mata tauira. Ko te uara pakeke Brinell te wāhanga i whiwhi mā te wehewehe i te kaha whakamātautau ki te horahanga mata o te porowhita kōpiko. Ki te whakaatuhia i roto i te HBS (pōro maitai), ko te waeine ko N/mm2 (MPa).
Ko te tātai tatau ko:
I roto i te tātai: F–te kaha whakamātautau i pēhia ki te mata o te tauira whakarewa, N;
D–Te whānui o te pōro maitai mō te whakamātautau, mm;
d–te whānui toharite o te kōhao, mm.
He tika ake, he pono ake hoki te ine i te pakeketanga o Brinell, engari ko te tikanga he pai anake te HBS mō ngā rauemi whakarewa kei raro iho i te 450N/mm2 (MPa), ā, kāore e pai mō te maitai pakeke ake, ngā pereti angiangi rānei. I roto i ngā paerewa paipa maitai, ko te pakeketanga o Brinell te mea e whakamahia whānuitia ana. Ko te diameter kōhao d te mea e whakamahia pinepinetia ana hei whakaatu i te pakeketanga o te rauemi, he mea ngāwari ki te mārama, he mea watea hoki.
Tauira: 120HBS10/1000130: Ko tōna tikanga ko te uara pakeke Brinell i inehia mā te whakamahi i tētahi pōro maitai 10mm te whānui i raro i te kaha whakamātautau o te 1000Kgf (9.807KN) mō te 30 hēkona (hēkona) ko te 120N/mm2 (MPa).
B. Te pakeke o Rockwell (HR)
He tikanga whakamātautau kōpikopiko te whakamātautau pakeke o Rockwell, pērā i te whakamātautau pakeke o Brinell. Ko te rerekētanga ko te ine i te hohonutanga o te kōpikopiko. Arā, i raro i te mahi ā-raupapa o te kaha whakamātautau tuatahi (Fo) me te kaha whakamātautau katoa (F), ka pēhia te kōpikopiko (te kōne, te pōro maitai rānei o te mira maitai) ki roto i te mata o te tauira. I muri i te wā pupuri kua tohua, ka tangohia te kaha matua. I te kaha whakamātautau, whakamahia te pikinga hohonu kōpikopiko toenga i inehia (e) hei tatau i te uara pakeke. Ko tōna uara he tau ingoamuna, e tohuhia ana e te tohu HR, ā, ko ngā tauine e whakamahia ana e 9 ngā tauine, tae atu ki te A, B, C, D, E, F, G, H, me te K. I roto i ēnei, ko ngā tauine e whakamahia whānuitia ana mō te whakamātautau pakeke maitai ko te A, B, me te C, arā, ko te HRA, HRB, me te HRC.
Ka tatauhia te uara pakeke mā te whakamahi i te tātai e whai ake nei:
I te whakamātautau me ngā tauine A me C, HR=100-e
I te whakamātautau me te tauine B, HR=130-e
I roto i te tātai, ko te e – te pikinga hohonu o te kōhao toenga e whakaatuhia ana i roto i te waeine kua tohua o te 0.002mm, arā, ina kotahi te waeine (0.002mm) te nekehanga tuaka o te kōhao, he rite ki te huringa o te pakeke o Rockwell mā te kotahi tau. Ko te nui ake o te uara e, ko te iti iho o te pakeke o te konganuku, ā, ko te ritenga kē.
Ko te whānuitanga e tika ana mō ngā tauine e toru i runga ake nei koia tēnei:
HRA (whakaurunga kōne taimana) 20-88
HRC (whakaurunga kōne taimana) 20-70
HRB (whakapūtanga pōro maitai 1.588mm te whānui) 20-100
Ko te whakamātautau pakeke o Rockwell tētahi tikanga e whakamahia whānuitia ana i tēnei wā, ā, ko te HRC te tuarua o ngā paerewa paipa maitai i muri i te pakeke o Brinell HB. Ka taea te whakamahi i te pakeke o Rockwell hei ine i ngā rauemi whakarewa mai i te tino ngohengohe ki te tino pakeke. Ka whakakapia ngā ngoikoretanga o te tikanga Brinell. He māmā ake i te tikanga Brinell, ā, ka taea te pānui tika i te uara pakeke mai i te mata o te mīhini pakeke. Heoi, nā te iti o te kōhao, kāore te uara pakeke i te tino tika pērā i te tikanga Brinell.
C. Te pakeketanga o Vickers (HV)
He tikanga whakamātautau kōpiko anō hoki te whakamātautau pakeke Vickers. Ka pēhia he kōpiko taimana tapawhā rite ki te piramita me te koki whakauru o te 1360 i waenganui i ngā mata rerekē ki roto i te mata whakamātautau i runga i te kaha whakamātautau kua tohua (F), ā, ka tangohia i muri i te wā pupuri kua tohua. Mā te kaha, inehia te roa o ngā hauroki e rua o te kōpiko.
Ko te uara pakeke Vickers te wāhanga o te kaha whakamātautau i wehea ki te horahanga mata kōpiko. Ko tōna tātai tatau ko:
I roto i te tātai: tohu mārō HV–Vickers, N/mm2 (MPa);
Te kaha whakamātautau-F, N;
d–te toharite tātaitanga o ngā hauroki e rua o te kōhao, mm.
Ko te kaha whakamātautau F i whakamahia i roto i te pakeke Vickers ko 5 (49.03), 10 (98.07), 20 (196.1), 30 (294.2), 50 (490.3), 100 (980.7) Kgf (N) me ētahi atu taumata e ono. Ka taea te ine i te uara pakeke. Ko te awhe ko 5~1000HV.
Tauira o te tikanga whakapuakitanga: Ko te tikanga o te 640HV30/20 ko te uara pakeke Vickers i inehia ki te kaha whakamātautau o te 30Hgf (294.2N) mō te 20S (hēkona) ko te 640N/mm2 (MPa).
Ka taea te whakamahi i te tikanga pakeke Vickers hei whakatau i te pakeke o ngā rauemi whakarewa tino angiangi me ngā paparanga mata. He painga matua ōna o ngā tikanga Brinell me Rockwell, ā, ka taea hoki te whakakore i ō rāua ngoikoretanga matua, engari ehara i te mea ngāwari pērā i te tikanga Rockwell. Kāore i te maha ngā whakamahinga o te tikanga Vickers i roto i ngā paerewa paipa maitai.
Wā tuku: Paenga-whāwhā-03-2024
