Hangarau whakarewa taiaho, nā te nui o te kaha, te iti o te wera e uru mai ana, me ngā āhuatanga kore-pa, kua noho ko tētahi o ngā tukanga matua o te hanga tino tika o ēnei rā. Heoi, ko ngā raruraru pēnei i te waikura, te porosity me te wera o ngā huānga i puta mai i te pa o te puna rewa ki te hau i te wā e whakarewa ana ka tino whakawhāiti i ngā āhuatanga miihini me te roa o te mahi o te hononga whakarewa. Hei reo matua mō te whakahaere i te taiao whakarewa, me hono te kōwhiringa o te momo, te tere rere me te aratau pupuhi o te hau tiaki ki ngā āhuatanga rauemi (pēnei i te mahi matū, te kawe wera) me te matotoru o te pereti.
Ngā momo hau tiaki
Ko te mahi matua o ngā hau tiaki kei te wehe i te hāora, te whakahaere i te whanonga o te puna rewa, me te whakapai ake i te whai huatanga o te hononga pūngao. I runga i ō rātou āhuatanga matū, ka taea te whakarōpū i ngā hau tiaki ki ngā hau kore mahi (argon, herium) me ngā hau hohe (hauota, hauhā waro). He tino pumau te matū o ngā hau kore mahi, ā, ka taea te ārai i te waikura o te puna rewa, engari ko ō rātou rerekētanga nui i roto i ngā āhuatanga ā-tinana wera ka pā nui ki te pānga whakarewa. Hei tauira, he nui te kiato o te argon (Ar) (1.784 kg/m³) ā, ka taea te hanga i tētahi paninga pumau, engari ko tōna kawe wera iti (0.0177 W/m·K) ka arahi ki te whakamatao puhoi o te puna rewa me te urunga papaku o te whakarewa. He rerekē, e waru ngā wā teitei ake te kawe wera o te herium (He) (0.1513 W/m·K) i te argon, ā, ka taea te whakatere i te whakamatao o te puna rewa me te whakanui ake i te urunga whakarewa, engari ko tōna kiato iti (0.1785 kg/m³) ka ngawari ki te mawhiti, me te hiahia kia nui ake te tere rere hei pupuri i te pānga tiaki. Ka taea e ngā hau hohe pēnei i te hauota (N₂) te whakarei ake i te kaha o te whakarewa mā te whakapakari i te otinga totoka i roto i ētahi āhuatanga, engari ko te whakamahinga nui rawa ka puta he porosity, he maturuturunga iho rānei o ngā āhua pakarukaru. Hei tauira, i te whakarewatanga o te maitai kore waikura takirua, ka taea e te horapa o te hauota ki roto i te puna rewa te whakararuraru i te taurite āhua ferrite/austenite, ka hua ake he hekenga o te ātete ki te waikura.
Ahua 1. Te whakarewatanga taiaho o te maitai kore waikura 304L (runga): Te parenga hau Ar; (raro): Te parenga hau N2
Mai i te tirohanga o te tikanga tukanga, ka taea e te kaha whakapūngao teitei o te helium (24.6 eV) te pehi i te pānga tiaki plasma me te whakarei ake i te mimiti kaha laser, ā, ka whakanui ake i te hohonutanga o te urunga. I taua wā, ko te kaha whakapūngao iti o te argon (15.8 eV) he ngāwari ki te whakaputa kapua plasma, e hiahia ana kia whakakorehia te arotahi, kia whakarerekētia rānei te pāorooro hei whakaiti i te pokanoa. Hei tāpiri, ko te tauhohenga matū i waenga i ngā hau hohe me te puna rewa (pēnei i te tauhohenga hauota me te Cr i roto i te maitai) ka whakarerekē pea i te hanganga whakarewa, ā, me whiriwhiri tupato i runga i ngā āhuatanga rauemi.
Ngā tauira tono rauemi:
• Rino: I roto i te whakarewanga pereti angiangi (<3 mm), ka taea e te argon te whakarite i te mutunga o te mata, me te matotoru o te paparanga waikura o te 0.5 μm anake mō te hononga whakarewa maitai waro-iti 1.5 mm; mō ngā pereti matotoru (>10 mm), me tāpiri he iti o te herium (He) hei whakanui ake i te hohonutanga o te urunga.
• Kowiri tira: Ka taea e te tiakitanga o te haukini te ārai i te ngaronga o te huānga Cr, me te ihirangi Cr o te 18.2% i roto i te hononga whakarewa kowiri tira 304 matotoru 3 mm e tata ana ki te 18.5% o te konganuku turanga; mō te kowiri tira takirua, me whai ranunga Ar-N₂ (N₂ ≤ 5%) hei taurite i te ōwehenga. Kua whakaatuhia e ngā rangahau ina whakamahia he ranunga Ar-2% N₂ mō te kowiri tira takirua 2205 matotoru 8 mm, he pumau te ōwehenga ferrite/austenite i te 48:52, me te kaha kume o te 780 MPa, he pai ake i te tiakitanga o te haukini parakore (720 MPa).
• Konumohe konumohe: Pereti angiangi (<3 mm): Ko te whakaata teitei o ngā konumohe konumohe ka hua ake he tere mimiti pūngao iti, ā, ka taea e te heriuma, me tōna pūngao ionization teitei (24.6 eV), te whakau i te plasma. E whakaatu ana ngā rangahau ina tiakina te konumohe konumohe 6061 he 2 mm te matotoru e te heriuma, ka eke te hohonutanga o te urunga ki te 1.8 mm, ka piki ake mā te 25% ki te whakataurite ki te argon, ā, he iti iho te tere porosity i te 1%. Mō ngā pereti matotoru (>5 mm): Me nui te kaha o te urunga o ngā pereti matotoru konumohe, ā, ka taea e te ranunga heriuma-argon (He:Ar = 3:1) te whakataurite i te hohonutanga o te urunga me te utu. Hei tauira, i te wā e whakarewahia ana ngā pereti 5083 he 8 mm te matotoru, ka eke te hohonutanga o te urunga ki te 6.2 mm i raro i te tiakitanga hau whakauru, ka piki ake mā te 35% ki te whakataurite ki te hau argon parakore, ā, ka whakaitihia te utu whakarewa mā te 20%.
Kia mōhio: Kei roto i te tuhinga taketake ētahi hapa me ētahi taupatupatu. Ko te whakamāoritanga i tukuna mai i ahu mai i te putanga kua whakatikatikaina, kua mārama hoki o te tuhinga.
Te awe o te tere rere o te hau argon
Ka pā tika te tere rere o te hau argon ki te kaha o te kapi hau me te hihiri wai o te puna rewa. Ina kore e ranea te tere rere, kāore e taea e te paparanga hau te wehe katoa i te hau, ā, ka ngāwari te taha o te puna rewa ki te waikura me te hanganga o ngā pūwero hau; ina nui rawa te tere rere, ka puta he pōrearea, ka taea te horoi i te mata o te puna rewa, ka arahi ki te hekenga whakarewa, ki te ruirui rānei. E ai ki te tau Reynolds o te tikanga wai (Re = ρvD/μ), ka piki ake te tere rere o te hau mēnā ka piki ake te tere rere. Ina neke ake te Re i te 2300, ka huri te rere laminar hei rere pōrearea, ka whakangaro i te pumau o te puna rewa. Nō reira, me tātari te whakatau i te tere rere matua mā roto i ngā whakamātautau, i ngā whakatauira tau rānei (pēnei i te CFD).
Pikitia 2. Ngā Pānga o ngā Rere Rere Hau Rerekē ki te Hononga Whakarewa
Me whakarerekē te arotautanga o te rere me te kawe wera o ngā rauemi me te matotoru o te pereti:
• Mō te maitai me te kowiri tira: Mō ngā pereti maitai angiangi (1-2 mm), ko te tere rere he pai ake kia 10-15 L/min. Mō ngā pereti matotoru (>6 mm), me whakanui ake ki te 18-22 L/min hei pehi i te waikura hiku. Hei tauira, ina 20 L/min te tere rere o te kowiri tira 316L matotoru 6 mm, ka pai ake te ōritetanga o te pakeke HAZ mā te 30%.
• Mō te koranu konumohe: Me tere te rere o te wai wera kia roa ake ai te wā tiaki. Mō te koranu konumohe 7075 he 3 mm te matotoru, ko te tere porosity te mea iti rawa (0.3%) ina he 25-30 L/min te tere rere. Heoi, mō ngā pereti matotoru rawa (>10 mm), me whakakotahi ki te pupuhi hiato hei karo i te aueue.
Te awe o te aratau pupuhi hau
Ka pā tika te aratau pupuhi hau ki te tauira rere o te puna rewa me te pānga pehi hapa mā te whakahaere i te ahunga me te tohatoha o te rere o te hau. Ka whakahaere te aratau pupuhi hau i te rere o te puna rewa mā te whakarerekē i te pikinga o te kukū mata me te rere o te Marangoni (rere o te Marangoni). Ka taea e te pupuhi taha te akiaki i te puna rewa kia rere i tētahi ahunga motuhake, ka whakaiti i ngā pore me te whakaurunga o te para; ka taea e te pupuhi hiato te whakapai ake i te ōritetanga o te hanganga whakarewa mā te whakataurite i te tohatoha pūngao mā te rere o te hau maha-aronga.
Ko ngā tikanga matua mō te pupuhi ko:
• Te pupuhi honohono: Ka tukuna te rere hau ki te hihi taiaho, ka hipokina te puna rewa kia ōrite, he pai mō te whakarewa tere-teitei. Ko tōna painga he pumau te tukanga, engari ka taea e te rere hau te whakararuraru i te arotahi taiaho. Hei tauira, ina whakamahia te pupuhi honohono ki runga i te pepa maitai whakapūmau motuka (1.2 mm), ka taea te whakanui ake i te tere whakarewa ki te 40 mm/s, ā, he iti iho i te 0.1 te tere o te ruirui.
• Te pupuhi taha: Ka tukuna te rere o te hau mai i te taha o te puna rewa, ka taea te whakamahi hei tango i ngā poke o te plasma, o raro rānei, he mea tika mō te whakarewa hohonu. Hei tauira, ina pupuhihia ki runga i te maitai Q345 matotoru 12 mm i te koki 30°, ka piki ake te whakarewa mā te 18%, ā, ka heke te tere o te pūngao o raro mai i te 4% ki te 0.8%.
• Te pupuhi whakakotahi: Mā te whakakotahi i te pupuhi coaxial me te pupuhi taha, ka taea te pehi i te waikura me te pokanoa plasma i te wā kotahi. Hei tauira, mō te konumohe konumohe 6061 matotoru 3 mm me te hoahoa pūwero takirua, ka whakaitihia te tere porosity mai i te 2.5% ki te 0.4%, ā, ka eke te kaha kume ki te 95% o te rauemi turanga.
Ko te awe o te hau ārai ki te kounga o te whakarewa e ahu mai ana i tana whakahaere i te whakawhiti pūngao, te pāmahana o te puna rewa, me ngā tauhohenga matū:
1. Whakawhiti pūngao: Mā te kawe wera nui o te hēriuma ka tere ake te whakamatao o te puna rewa, ka whakaitihia te whānui o te rohe e pāngia ana e te wera (HAZ); mā te kawe wera iti o te argon ka roa ake te noho o te puna rewa, he mea pai mō te hanganga mata o ngā pereti angiangi.
2. Te pumau o te puna rewa: Ka pā te rere o te hau ki te rere o te puna rewa mā te kaha kutikuti, ā, mā te tere rere tika ka taea te pehi i te tauhiuhi; ka puta he awhiowhio i te tere rere nui rawa, ka hua ake he hapa whakarewa.
3. Tiakitanga matū: Ka wehea te hāora e ngā hau kore mahi, ā, ka ārai i te waikura o ngā huānga koranu (pērā i te Cr, Al); ka huri ngā hau hohe (pērā i te N₂) i ngā āhuatanga whakarewa mā te whakapakari i te wairewa totoka, te hanganga matū rānei, engari me tino whakahaere te kukū.
Wā tuku: Paenga-whāwhā-09-2025
