Ukuveliswa kwe-HIC Resistant Steels

I-Hydrogen induced cracking (HIC) imele umngeni oqhelekileyo, ngokukodwa kwi-petroleum kunye neshishini lokucoca apho ukucoceka kunye nomgangatho opheleleyo wentsimbi kubaluleke kakhulu.

Inkqubo yemveliso yeentsimbi ezixhathisayo ze-HIC ibandakanya ubuchule obubalulekileyo be-desulphurization kubandakanya inaliti ye-magnesium kunye nokuvuselela ngesitofu se-argon esezantsi.

Ukuveliswa kwentsimbi ecocekileyo kusekelwe kwiiteknoloji zokulawula kunye / okanye ukususa ukufakwa kwintsimbi. Ngokuqhelekileyo, iintlobo kunye neempawu ze-non-metallic inclusions kwi-steel zinempembelelo enkulu kwiipropati ze-mechanical zetsimbi kunye nokumisela ukucoceka kwentsimbi. Uhlalutyo oluchanekileyo lwezi mpawu ke ngoko luyafuneka ukuze kwandiswe inkqubo yokwenza intsimbi ukuvelisa iintsimbi ezisemgangathweni.

I-Hydrogen-induced cracking (HIC) kunye ne-sulphide stress cracking (SSC) imele iindidi ezimbini zomonakalo owenziwe yi-hydrogen odityaniswa rhoqo kwi-petroleum kunye ne-refinery industry. Kwimeko yokuqala (HIC), ngokuqhelekileyo iyaqatshelwa ukuba ukuchasana kweentsimbi kuxhomekeke ngokukodwa kwiimpawu zabo ze-microstructural - ukubandakanywa okungezona isinyithi kunye neebhendi zokwahlula.

I-manganese sulfide ezongeziweyo zithathwa njengezona ndawo ziyingozi zokuqalisa. Kwimeko yesibini (SSC), kukholelwa ukuba ukuchasana kweentsimbi kunokukhethwa ngokufanelekileyo kwinqanaba lamandla abo ngelixa iimpawu ze-microstructure zingabalulekanga kangako. Iphepha elinikezelweyo linikezelwe kwisifundo se-HIC kunye ne-SSC kwiinsimbi ze-carbon-manganese, ezihluke kunyango lwazo lokushisa (i-microstructure, inqanaba leempawu zomatshini) kunye nokucoceka kwazo.

Ukufakwa kwe-MnS ngoyena mqalisi oyingozi kakhulu we-HIC, ngoko ke, njengomlinganiselo osisiseko, umxholo wesulfure kufuneka uncitshiswe kwiintsimbi ezisetyenziswa kwiindawo ezineasidi. Ngenxa yenkqubela phambili kwinkqubo yokwenza isinyithi, umxholo wesulfure unokuncitshiswa ukuya kwinqanaba eliphantsi kakhulu; ngaphantsi kwe-0.0008 wt. % (8ppm).

Unyango lwe-Ca ludla ngokusetyenziswa ukuze kuthintelwe ukubunjwa kwe-MnS emide kunye nokulawula ukubandakanywa kwesulfide kwimilo engqukuva, kwaye ukuba kukho umxholo we-Ca ofanelekileyo wepropathi yokumelana nokuqhekeka. Ukuba umxholo we-Ca uphezulu xa uthelekiswa nomxholo we-S, i-Ca engaphezulu inokwenza i-oxides enokuthi isebenze njengomqalisi we-HIC. Iiparamitha ezininzi ezimele umxholo we-Ca osebenzayo zaziswa, kwaye umxholo weCa kufuneka ulawulwe ngononophelo kuluhlu olumxinwa; umzekelo, 3

Itheyibhile 1: Iimfuno zokwakhiwa kweekhemikhali zentsimbi yombhobho wokuqina, [ppm]

Umzobo 1 ubonisa indlela yokuvelisa i-HIC ukumelana nentsimbi. Ngaphambi kwenkqubo ye-BOF, isinyithi esishushu sichithwa kwisikhululo se-metal desulphurization ngokutofa kwe-magnesium kunye ne-CaO. Kwi-BOF, kufuneka kuhlawulwe kuphela iziqwenga ezinesulfure ephantsi. I-aluminium ye-deoxidation kunye ne-slag forming agents zongezwa ngexesha lokubetha. I-alloying engundoqo nayo iqhutywe ngelo xesha.

Emva koko i-ladle ihanjiswa kwisikhululo esiqhekezayo apho i-argon ivuthelwa ngomkhonto ophezulu ukwenzela ukuxuba isinyithi kunye ne-slag ngenjongo ye-desulphurization. Emva koko, i-ladle idluliselwa kunyango lwe-vacuum. Intsimbi ishukunyiswa yinaliti ye-argon esezantsi ukuqinisekisa i-desulphurization enzulu kunye ne-degassing.