Kusanthula kwa Kupanga ndi Kuphwanyika kwa Phosphorus Segregation mu Carbon Structural Steel
Pakalipano, zodziwika bwino za carbon structural steel waya ndodo ndi mipiringidzo yoperekedwa ndi zitsulo zapakhomo ndi φ5.5-φ45, ndipo okhwima kwambiri ndi φ6.5-φ30.Pali ngozi zambiri zabwino zomwe zimachitika chifukwa cha kusiyana kwa phosphorous mu ndodo yaying'ono yama waya ndi zida zopangira.Tiyeni tikambirane za chikoka cha tsankho phosphorous ndi kusanthula mapangidwe ming'alu wanu umboni.
Kuphatikiza kwa phosphorous ku chitsulo kumathanso kutseka gawo la austenite gawo mu chithunzi cha iron-carbon phase.Choncho, mtunda pakati pa solidus ndi liquidus uyenera kukulitsidwa.Chitsulo chokhala ndi phosphorous chikakhazikika kuchokera kumadzi kupita ku cholimba, chiyenera kudutsa kutentha kwakukulu.Kufalikira kwa phosphorous muzitsulo kumachepa.Panthawiyi, chitsulo chosungunula chokhala ndi phosphorous yambiri (chinthu chochepa chosungunuka) chimadzazidwa ndi mipata pakati pa dendrites yoyamba yolimba, motero kupanga kusiyana kwa phosphorous.
Mumutu wozizira kapena kuzizira kwa extrusion, zinthu zosweka nthawi zambiri zimawonedwa.Kuwunika kwazitsulo ndi kusanthula kwa zinthu zowonongeka kumasonyeza kuti ferrite ndi pearlite zimagawidwa m'magulu, ndipo mzere wachitsulo woyera ukhoza kuwoneka bwino mu matrix.Pa ferrite, pamakhala zophatikizika zowoneka ngati bandeji zowoneka bwino za sulfide pamatrix opangidwa ndi gululi.Kapangidwe kameneka kamene kamapangidwa ndi kugawanika kwa sulfure phosphide kumatchedwa "ghost line".Izi ndichifukwa choti dera lokhala ndi phosphorous m'dera lomwe lili ndi tsankho lalikulu la phosphorous limawoneka loyera komanso lowala.Chifukwa cha kuchuluka kwa phosphorous mu lamba woyera ndi wowala, mpweya wa kaboni mu lamba wa phosphorous-wowonjezera woyera ndi wowala umachepetsedwa kapena mpweya wa carbon ndi wochepa kwambiri.Mwanjira iyi, makhiristo amtundu wa slab mosalekeza amakula molunjika pakati pomwe lamba wopangidwa ndi phosphorous mosalekeza..Billet ikakhazikika, ma austenite dendrites amayamba kusungunuka kuchokera kuchitsulo chosungunuka.Phosphorous ndi sulfure zomwe zili mu dendrites zimachepetsedwa, koma chitsulo chosungunuka chokhazikika chimakhala ndi phosphorous ndi zinthu zonyansa za sulfure, zomwe zimakhazikika pakati pa dendrite oxis, chifukwa cha kuchuluka kwa phosphorous ndi sulfure, sulfure idzapanga sulfide, phosphorous idzasungunuka mu matrix.Sizophweka kufalitsa ndipo zimakhala ndi zotsatira za kutulutsa mpweya.Mpweya sungathe kusungunuka, kotero kuzungulira phosphorous yankho lolimba (Mbali za ferrite white band) zimakhala ndi mpweya wambiri.Mpweya chinthu mbali zonse za lamba ferrite, ndiko kuti, mbali zonse za phosphorous-wolemera dera, motero kupanga yopapatiza, wapakatikati pearlite lamba kufanana ferrite lamba woyera, ndi moyandikana yachibadwa minofu Osiyana.Pamene billet imatenthedwa ndikukanikizidwa, ma shafts amapitilira njira yoyendetsera.Ndi chifukwa chakuti gulu la ferrite lili ndi phosphorous yambiri, ndiye kuti, kusiyana kwakukulu kwa phosphorous kumabweretsa mapangidwe a gulu lalikulu komanso lowala kwambiri la ferrite, ndi chitsulo chodziwikiratu. element body.Gulu la ferrite lokhala ndi phosphorous lokhala ndi timizere tambiri ta sulfide ndi lomwe timakonda kulitcha gulu la "ghost line" (onani Chithunzi 1-2).
Chithunzi 1 Ghost waya mu carbon steel SWRCH35K 200X
Chithunzi 2 Ghost waya mu plain carbon steel Q235 500X
Chitsulo chikatenthedwa, malinga ngati pali kusiyana kwa phosphorous mu billet, ndizosatheka kupeza microstructure yofanana.Komanso, chifukwa cha tsankho lalikulu la phosphorous, mawonekedwe a "ghost wire" apangidwa, omwe mosakayikira amachepetsa makina azinthuzo..
Kugawanika kwa phosphorous mu carbon zitsulo ndizofala, koma digiriyi ndi yosiyana.Pamene phosphorous imasiyanitsidwa kwambiri (mawonekedwe a "ghost line" akuwonekera), zidzabweretsa zotsatira zoyipa kwambiri kuchitsulo.Mwachiwonekere, kulekanitsa kwakukulu kwa phosphorous ndi chifukwa cha kusweka kwa zinthu panthawi yozizira.Chifukwa mbewu zosiyanasiyana muzitsulo zimakhala ndi phosphorous yosiyana, zinthuzo zimakhala ndi mphamvu ndi kuuma kosiyana;komano, ndizopanganso kuti zinthuzo zibweretse kupsinjika kwamkati, zidzalimbikitsa zinthuzo kuti zikhale zosavuta kusweka mkati.Muzinthu zomwe zili ndi "ghost wire" ndizomwe zimachepetsera kuuma, mphamvu, elongation pambuyo pa kusweka ndi kuchepetsa dera, makamaka kuchepetsa kulimba kwamphamvu, zomwe zidzatsogolera kuzizira kwa zinthuzo, kotero kuti phosphorous zili mkati. ndi zomangamanga zachitsulo Khalani ndi ubale wapamtima kwambiri.
Kuzindikira kwa Metallographic Mu minofu ya "ghost line" pakatikati pa malo owonera, pali ma sulfide ambiri otuwa.The sanali zitsulo inclusions mu structural zitsulo makamaka amakhala mu mawonekedwe a oxides ndi sulfides.Malinga ndi GB/T10561-2005 "Standard Grading Chart Microscopic Inspection Method for Content of Non-metallic Inclusions mu Zitsulo", zophatikizika za Type B zimakhudzidwa panthawiyi Zinthu zakuthupi zimafika pa 2.5 ndi kupitilira apo.Monga ife tonse tikudziwira, osakhala zitsulo inclusions ndi magwero a ming'alu.Kukhalapo kwawo kudzawononga kwambiri kupitiriza ndi kugwirizanitsa kwa microstructure yachitsulo, ndikuchepetsa kwambiri mphamvu ya intergranular yachitsulo.Zimatengedwa kuchokera ku izi kuti kukhalapo kwa sulfides mu "mzere wa mzimu" wa mkati mwa chitsulo ndi malo omwe amatha kusweka.Choncho, ozizira kupanga ming'alu ndi kutentha mankhwala kuzimitsa ming'alu ambiri malo fastener kupanga amayamba ndi kuchuluka kwa kuwala imvi woonda sulfides.Maonekedwe a nsalu zoipa zoterezi amawononga kupitiriza kwa zitsulo katundu ndipo kumawonjezera chiopsezo cha kutentha mankhwala."Ulusi wa ghost" sungathe kuchotsedwa ndi normalizing, ndi zina zotero, ndipo zinthu zosadetsedwa ziyenera kuyendetsedwa mosamalitsa kuchokera ku smelting kapena zipangizo zisanalowe mufakitale.
Zosakaniza zopanda zitsulo zimagawidwa kukhala alumina (mtundu A) silicate (mtundu C) ndi oxide spherical (mtundu D) malinga ndi kapangidwe kawo ndi kupunduka.Kukhalapo kwawo kumadula kupitiriza kwa chitsulo, ndipo maenje kapena ming'alu amapangidwa pambuyo popukuta.Ndikosavuta kupanga gwero la ming'alu panthawi yakuzizira ndikuyambitsa kupsinjika panthawi ya chithandizo cha kutentha, zomwe zimapangitsa kuti ming'alu iwonongeke.Chifukwa chake, zophatikiza zopanda zitsulo ziyenera kuyendetsedwa mosamalitsa.Zitsulo zamakono za GB / T700-2006 "Carbon Structural Steel" ndi GB/T699-2016 "Carbon Structural Steel" yapamwamba kwambiri sizimapanga zofunikira zomveka bwino zazitsulo zopanda zitsulo..Pazigawo zofunika, mizere yokhotakhota komanso yowoneka bwino ya A, B, ndi C nthawi zambiri sapitilira 1.5, ndipo D ndi Ds mizere yokhotakhota ndi yabwino sipitilira 2.
Nthawi yotumiza: Oct-21-2021
