Ngā Momo Kowiri tira e Whā me te Tūranga o ngā Huānga Whakakotahi:
E whā ngā momo matua o te maitai kore waikura: te maitai austenitic, te maitai martensitic, te maitai ferritic, me te maitai kore waikura takirua (Ripanga 1). E hangai ana tēnei whakarōpūtanga ki te hanganga moroiti o te maitai kore waikura i te pāmahana rūma. Ina whakamahanahia te maitai waro-iti ki te 1550°C, ka huri tōna hanganga moroiti mai i te ferrite pāmahana rūma ki te austenite. Ina whakamataohia, ka hoki te hanganga moroiti ki te ferrite. Ko te Austenite, e noho ana i ngā pāmahana teitei, he kore-aukume, ā, he iti ake te kaha engari he pai ake te ngāwari ki te whakataurite ki te ferrite pāmahana rūma.
Ina neke atu i te 16% te nui o te chromium (Cr) i roto i te maitai, ka pumau te hanganga iti o te pāmahana rūma i roto i te wāhanga ferrite, ka mau tonu te ferrite i ngā awhe pāmahana katoa. Ka kiia tēnei momo ko te maitai kore waikura ferritic. Ina neke atu i te 17% te nui o te chromium (Cr) me te neke atu i te 7% te nui o te nickel (Ni), ka pumau te wāhanga austenite, ka mau tonu te austenite mai i te pāmahana iti tae noa ki te ira rewa.
Ko te maitai kore waikura austenitic e kiia ana ko te momo "Cr-N", ko ngā maitai kore waikura martensitic me te ferritic e kiia tika ana ko te momo "Cr". Ka taea te whakarōpū i ngā huānga o te maitai kore waikura me ngā konganuku whakakī ki ngā huānga hanga-austenite me ngā huānga hanga-ferrite. Ko ngā huānga hanga-austenite tuatahi ko te Ni, C, Mn, me te N, ko ngā huānga hanga-ferrite tuatahi ko te Cr, Si, Mo, me te Nb. Mā te whakarerekē i te ihirangi o ēnei huānga ka taea te whakahaere i te ōwehenga o te ferrite i roto i te hononga whakarewa.
He māmā ake te whakarewa i te maitai kore waikura austenitic, ina koa he iti iho i te 5% te hauota (N), ā, he pai ake te kounga whakarewa i ngā maitai kore waikura he iti ake te ihirangi N. He pai te kaha me te ngāwari o ngā hononga whakarewa maitai kore waikura austenitic, ā, he maha ngā wā ka kore e hiahiatia he maimoatanga wera i mua i te whakarewanga me muri i te whakarewanga. I roto i te mara o te whakarewa maitai kore waikura, e 80% o ngā whakamahinga katoa o te maitai kore waikura te maitai kore waikura austenitic, koia te kaupapa matua o tēnei tuhinga.
Me pēhea te whiriwhiri i te mea tikawhakarewa maitai kore waikurangā taonga pau, ngā waea me ngā hikohiko?
Mena he rite te rauemi matua, ko te ture tuatahi ko te "whakataurite i te rauemi matua." Hei tauira, mena ka honoa te waro ki te maitai kore waikura 310, 316 rānei, whiriwhiria te rauemi waro e rite ana. I te wā e whakarewa ana i ngā rauemi rerekē, whai i te aratohu mō te whiriwhiri i tētahi rauemi turanga e rite ana ki te nui o te ihirangi huānga whakarewa. Hei tauira, i te wā e whakarewa ana i te maitai kore waikura 304 me te 316, whiriwhiria ngā mea whakarewa momo 316. Heoi, he maha anō ngā take motuhake kāore e whaihia te mātāpono o te "whakataurite i te konganuku turanga". I tēnei horopaki, he mea tika kia "tirohia te tūtohi whiriwhiri mea whakarewa." Hei tauira, ko te maitai kore waikura momo 304 te rauemi turanga tino noa, engari kāore he momo tokotoko whakarewa 304.
Mena me ōrite te rauemi whakarewa ki te konganuku turanga, me pēhea te whiriwhiri i te rauemi whakarewa hei whakarewa i te waea me te hiko kowiri tira 304?
I te wā e whakarewahia ana te maitai kore waikura 304, whakamahia ngā taputapu whakarewa momo 308 nā te mea ka taea e ngā huānga tāpiri o te maitai kore waikura 308 te whakau ake i te wāhi whakarewa. He kōwhiringa pai hoki te 308L. Ko te L e tohu ana i te iti o te ihirangi waro, ko te maitai kore waikura 3XX e tohu ana i te ihirangi waro o te 0.03%, ko te maitai kore waikura paerewa 3XX ka taea te whakauru ki te 0.08% te ihirangi waro. I te mea kei roto ngā taputapu whakarewa momo-L i te momo whakarōpūtanga kotahi ki ngā taputapu whakarewa kore-momo-L, me whakaaro ngā kaihanga ki te whakamahi motuhake i ngā taputapu whakarewa momo-L nā te mea ka taea e tōna ihirangi waro iti te whakaiti i te ia o te waikura intergranular. Inaa, e whakapono ana te kaituhi mena kei te hiahia ngā kaihanga ki te whakapai ake i ā rātou hua, ka nui ake te whakamahinga o ngā rauemi kōwhai āhua-L. Kei te whakaaro hoki ngā kaihanga e whakamahi ana i ngā tikanga whakarewa GMAW ki te whakamahi i te maitai kore waikura momo 3XXSi nā te mea ka taea e te SI te whakapai ake i ngā wāhanga makuku me te turuturu. Mēnā he teitei ake te tihi o te wahi waro, he ngoikore rānei te hononga o te puna whakarewa i te matimati whakarewa o te tuitui puhoi koki, te tuitui whānui rānei, mā te whakamahi i te waea whakarewa kua āraia ki te hau kei roto ko te S ka taea te whakamakuku i te tuitui waro me te whakapai ake i te tere whakatakotoranga.
Wā tuku: Hepetema-26-2023