Feem ntau, cov txheej txheem ntau lawm ntawm seamless steel raj tuaj yeem muab faib ua ob pawg: kev kos duab txias thiab kub dov. Kub dov, raws li lub npe qhia, suav nrog dov ntawm qhov kub thiab txias, uas txo cov deformation tsis kam thiab tso cai rau kev deformation tseem ceeb. Noj cov dov ntawm steel daim hlau ua piv txwv, cov tuab tuab ntawm cov nruam casting slab yog nyob ib ncig ntawm 230mm, uas, tom qab roughing thiab tiav, yuav txo tau mus rau ib tug zaum kawg thickness ntawm 1-20 hli. Ntxiv mus, vim qhov me me dav-rau-thickness piv ntawm steel daim hlau thiab qis dua qhov tseeb qhov yuav tsum tau, cov teeb meem ntawm phaj tsis tshua muaj tshwm sim, nrog rau qhov tseem ceeb ntawm kev tswj convexity.
Kub dov seamless steel raj xa mus rau cov txheej txheem uas dov yuav siv qhov chaw saum toj no lub recrystallization kub, nyob rau hauv sib piv rau txias dov, uas tshwm sim hauv qab no kub.
Qhov zoo:
Nws tuaj yeem cuam tshuam cov qauv ntawm cov hlau ingots, ua kom cov nplej loj ntawm cov hlau, thiab tshem tawm qhov tsis xws luag hauv microstructure, uas ua rau cov qauv hlau denser thiab txhim kho cov khoom siv kho tshuab, tshwj xeeb tshaj yog nyob rau hauv cov kev taw qhia dov. Qhov kev hloov pauv no ua rau cov hlau tsis muaj isotropic rau qee yam.
Npuas, tawg, thiab porosity tsim thaum lub sij hawm casting tuaj yeem welded kaw nyob rau hauv qhov kub thiab txias.
Qhov tsis zoo:
Tom qab kub dov, tsis yog-hlau inclusions (feem ntau sulfides, oxides, thiab silicates) nyob rau hauv cov hlau yog compressed rau hauv nyias txheej, ua rau lamination los yog interlayering. Qhov lamination no ua rau cov hlau tsis muaj zog tensile raws lub thickness kev taw qhia thiab tej zaum yuav ua rau interlayer tearing thaum weld contraction. Cov kab mob hauv zos uas raug cuam tshuam los ntawm kev sib txuas ntawm weld feem ntau tuaj yeem ncav cuag ob peb zaug ntawm qhov taw tes tawm los, ntau tshaj li hom kab mob tshwm sim los ntawm kev thauj khoom.
Seamless steel raj yog tsim los ntawm kev ua haujlwm kub xws li tho thiab kub dov, tsis muaj vuam seams. Thaum tsim nyog, cov hlab ntsha tuaj yeem ua haujlwm txias ntxiv tom qab ua haujlwm kub kom ua tiav cov duab xav tau, qhov loj me, thiab cov khoom. Tam sim no, seamless steel raj (DN15-600) yog cov kav dej siv dav tshaj plaws hauv cov chaw tsim khoom petrochemical.
Raws li kev tsim cov txheej txheem, seamless steel raj tau ntxiv rau hauv cov kub dov (los yog extruded) seamless steel hlab thiab txias-draw (los yog txias-dov) seamless steel hlab. Cold-drawn (los yog txias-dov) raj tau muab faib ua cov raj puag ncig thiab cov raj tshwj xeeb.
a. Txheej txheem cej luam ntawm cov txheej txheem ntau lawm:
Kub dov (los yog Extruded) Seamless Steel Tubes: Round billet → Cua sov → Piercing → Peb-yob skew dov, nruam dov, los yog extrusion → Tube stripping → Sizing (los yog txo) → Txias → Tube blank → Straightening → Hydrostatic testing (los yog Kev kuaj pom qhov tsis haum) → Marking → Warehousing.
Cold-drawn (los yog Cold-rolled) Seamless Steel Tubes: Round billet → Cua sov → Piercing → Heading → Annealing → Pickling → Roj txheej (los yog tooj liab plating) → Multi-theem txias txias (los yog txias dov) → Tube blank → Thaum tshav kub kub kho → Ncaj nraim → Hydrostatic testing (los yog qhov tsis zoo) → Marking → Warehouse.
