Theknoloji ea Direct Hot Rolling ea Continuous Casting Billet (CC-HDR)

Sethaleng sa pele sa continuous casting process, the section of the cast slab is small, the temperature drops quickly, and the quality of the cast slab is poor. Therefore, surface finishing is required before rolling, so cold billet reheating is used. This wastes a lot of energy. In the 1980s, after long-term research, Nippon Steel Corporation successfully developed wide-section continuous casting slab hot delivery and hot charging and even hot direct rolling processes, which greatly improved the compactness of continuous casting and continuous rolling. Significantly save energy. In order to realize the hot delivery and direct rolling of continuous casting billets, the following complete sets of technologies are required as a guarantee, namely:

(1) Theknoloji ea ho etsa letlapa le se nang sekoli;

(2) Theknoloji ea ho lemoha Inthaneteng bakeng sa liphoso tsa slab;

(3) Ho sebelisa mocheso o patehileng oa ho tiisa ho hlahisa theknoloji e phahameng ea mocheso e tsoelang pele ea ho lahla;

(4) Theknoloji ea ho fetola bophara ba slab ka potlako Inthaneteng;

(5) Theknoloji e tsoelang pele ea ho futhumatsa le ho theola mocheso;

(6) Tsamaiso ea lik’homphieutha le tsamaiso ea kemiso bakeng sa ts’ebetso.

Ho ea ka maemo a fapaneng a mocheso oa slab a ka fumanoang, ts’ebetso e tsoelang pele ea ho kopanya-ho tsoela pele e ka aroloa ka:

(1) Ho fana ka mocheso o tlase oa mocheso oa mokhoa o tsoelang pele oa ho lahla slab-reheating (ho tloha holimo);

(2) Tsoela pele ho lahlela billet mocheso o phahameng oa ho fana ka mocheso le ts’ebetso e potlakileng ea ho futhumatsa hape (ka holimo e ntle haholo);

(3) Ts’ebetso e tsoelang pele ea ho lahla billet (ho futhumatsa likhutlo tse ‘nè) mokhoa o tobileng oa ho roala.

Semela sa Sakai sa Nippon Steel se ntse se tsoela pele ho sebelisa matšeliso a mocheso oa motlakase oa motlakase oa motlakase (ETC) bakeng sa likhutlo tse ‘nè tsa letlapa le nang le mocheso o phahameng, le ka phuthoang ka ho toba ho li-coil tse kolobisitsoeng.

Limela tse kholo tsa tšepe naheng ea heso (tse kang Baosteel, joalo-joalo) tse hlahisang lipoleiti tsa boleng bo phahameng li boetse li atlehile ho finyella ho chesa ka ho toba ha li-slabs tse tsoelang pele.

Near-net-shape continuous casting (thin slab continuous casting) ke ts’ebetso e ncha e tsoelang pele ea ho akhela e ntlafalitsoeng ka bo-1990. Ho tloha ha e tsoaloa, e entsoe e le mohala o tsoelang pele oa tlhahiso o nang le leloala le sa khaotseng. Ha billet e tsoelang pele ea ho lahla e sa tiisoa ka ho feletseng, ho fokotseha ha leseli ho ka etsoa Inthaneteng, ‘me mocheso oa billet o tsoelang pele o ka bolokoa ka holim’a mohala ha o kena leloaleng la ho roala, ke hore, ha o e-s’o kene phetoho ho tloha austenite ( Y phase) ho ferrite (mohato). E phuthetsoe ka lakane ea tšepe ka kotloloho sebakeng sa mokhahlelo oa mantlha oa austenite. Litsebi tsa Machaena li fumane hore tšepe e hlahisoang ka tsela ena ha e hlahise austenite ea bobeli nakong ea ho thetheha (a ^7) le ho qhibiliha ho tšoanang ha karolo ea pula e qhalakaneng, kahoo poleiti e tšesaane e hlahisoang ke haufi-le-net-shape continuous casting Precipitation hardening precipitates can e be likaroloana tsa nano-size, tse nang le phello e babatsehang boleng ba tšepe. naha ea heso e hahile mela e 12 ea tlhahiso bakeng sa letlapa le lesesaane le tsoelang pele, ‘me tlhahiso ea selemo le selemo e nka boemo ba bohlokoa haholo lefatšeng.

Billet e tswelang pele ho lahla ha e le hantle e haufi le-net-shape e tswelang pele. E ile ea etsoa lipatlisiso le ho ntlafatsoa pejana, ‘me ea sebelisoa ka katleho lilemong tsa bo-1960. Ka lebaka la tsebo le boemo bo felletseng ba tekheniki ka nako eo, ho ne ho sebelisoa hangata ho futhumatsa billet. naha ea heso e khothalelitse ka matla thekenoloji e tsoelang pele ea ho lahlela billet lilemong tsa bo-1980, ho kopantsoe le maemo a naha ea heso, ho kopantsoe le li-converter tse nyane (30t) le liloala tse nang le melamu ea lebelo le phahameng ho theha mohala o akaretsang oa lihlahisoa tse telele tsa k’habone, ka tlhahiso e phahameng (e ngata haholo). ea ba nang le tlhahiso ea selemo le selemo ea lithane tse limilione tse 1 kapa ho feta) ), ka lichelete tse tlaase le tlhōlisano e matla ea tšepe bakeng sa kaho. Tlhokahalo ea tšepe ea kaho naheng ea heso e kholo, ‘me maraka a nako e telele a lihlahisoa a boetse a pharaletseng haholo. Ka hona, mohala ona o monyenyane o tsoelang pele oa ho lahlela leloala la terata ka lebelo le phahameng o nka karolo e kholo ea tlhahiso ea tšepe ea naha ea heso. Ho phaella moo, billet tsoela pele ho lahlela e boetse e na le melemo e itseng ka tlaase-alloy tšepe sebopeho lihlahisoa tse telele (tse kang bolo behang tšepe, tšepe bakeng sa tlhahiso ea mechine). E le ho ntlafatsa katleho ea tlhahiso le ho boloka matla, ho fana ka ho chesa le ho tjhaja ho chesang ha li-cast slabs ho boetse ho lebisitsoe tlhokomelo e eketsehileng. Leha ho le joalo, ho lekanyelitsoe ho maemo a pele a moralo, ha ho sa le bonolo hore mocheso oa slab o fihle ho 700 RON, ‘me mehato e mengata ea ho boloka mocheso e lokela ho nkoa. Ho futhumatsa hape ha billet hangata ho sebelisa sebōpi se tukang ka mafura. naha ea heso Zhenwu Electric Furnace Co., Ltd. e hlahisitse le ho theha mokhoa oa ho futhumatsa ka potlako marang-rang a li-cast slabs ka induction ea electromagnetic. Melemo ea eona ke e latelang:

(1) Nako ea ho futhumatsa ea billet ka seboping sa maqhubu a mahareng e khuts’oane haholo ho feta nako e hlokahalang hore e chesoe ka seboping sa mollo, e sa thuseng feela ho fokotsa tahlehelo ea tšepe, empa hape e ntlafatsa boleng ba bokaholimo ba sebopi. letlapa nakong ea ho roala;

(2) U sebelisa mocheso oa motlakase oa motlakase, ha ho na lihlahisoa tse tukang sebakeng sa ho futhumatsa, ka hona ho qoba oxidation le decarburization ea slab ea cast, e le hore ho ka fumanoa billet e hloekileng ka ho futhumatsa hona ka potlako;

(3) Kaha sebōpi sa ho futhumatsa ha induction ha se na lihlahisoa tse tukang, se na le tikoloho ebile se fokotsa mahlaseli a mocheso haholo;

(4) Sebōpi sa ho futhumatsa ha induction ha se bonolo feela, se potlakile ebile se nepahetse ho laola mocheso ka bohona, empa hape se ka boloka matla;

(5) Sebōpi sa ho futhumatsa ka induction se sebelisetsoa ho futhumatsa billet, ‘me litšenyehelo tsa tlhokomelo ea thepa li nyenyane haholo ho feta tsa sebōpi sa mollo;

(6) Li-billet tsa ho futhumatsa ka induction li ka futhumatsa li-billet tse telele ka mokhoa o bonolo haholoanyane, ho leng molemo ho hlokomela ho bilika ho sa feleng le ho ntlafatsa ts’ebetso ea rolling.