Yog vim li cas, cuam tshuam thiab tiv thaiv ntawm stratification ntawm Square Tube Billets

Laying ntawm lub billet yog hais txog qhov tshwm sim uas txheej txheej -zoo li hlau sib cais tshwm sim thaum uas tig mus rau lub dov kev taw qhia nyob rau hauv lub billet (rau seamless square tubes, nws sib raug rau lub voj voos billet; rau txias - tsim thiab welded square raj, nws sib raug rau steel phaj los yog strip billet). Qhov no yog concealed internal defect. Qhov ua rau tuaj yeem muab faib ua ob pawg loj:inherent metallurgical defects thiab induced los ntawm cov txheej txheem tom ntej. Thaum kawg, nws nthuav mus rau hauv macroscopic txheej thaum lub sij hawm yas deformation txheej txheem.

• Aggregation ntawm non{0}}hlausuav nrog: Thaum lub sij hawm steelmaking, tsis tiav deoxidation thiab tsis txaus cua tshuab nyob rau hauv refining, raws li zoo raws li scale tsim los yog yaig ntawm refractory cov ntaub ntawv, yuav ua rau siab -melting- taw tes nyuaj inclusions xws li Al₂O₃, sulfides, thiab calcium{2}} aluminate seem nyob rau hauv lub molten steel. Cov inclusions no tsis muaj plasticity thiab, thaum lub sij hawm dov, yog elongated rau nyias, tsis muaj zog txheej, ua lub hauv paus ntawm lub interface rau delamination.
• Internal defects ntawm nruam casting billets: Thaum lub sij hawm nruam casting txheej txheem, lub hauv paus porosity, shrinkage kab noj hniav, thiab subsurface npuas yuav nyob twj ywm yog hais tias lawv tsis tiav welded thaum lub sij hawm tom ntej dov. Lawv yuav raug nias rau hauv txheej txheej; Nyob rau tib lub sijhawm, kev sib cais hauv nruab nrab ntawm cov pa roj carbon monoxide thiab cov qauv banded tuaj yeem ua rau cov khoom tsis sib xws ntawm tus ntoo khaub lig- ntu, thiab lub zog sib txuas ntawm thaj chaw sib cais yog qis dua li ntawm matrix, ua rau nws yooj yim rau kev sib cais hauv kev ntxhov siab.

• Cov cua kub tsis sib xws thiab qhov kub tsis zoo:Yog hais tias lub raj xa dej tsis tau rhuab kom huv si los yog muaj qhov sib txawv ntawm qhov kub thiab txias ntawm tus ntoo khaub lig- ntu (feem ntau hu ua "yin- yang nto"), nws yuav ua rau cov hlau tsis sib xws, thiab thaum lub sij hawm deformation, interlayer shear stress yuav dhau lub zog ntawm kev sib txuas, ua rau kev sib cais ntawm qhov tsis muaj zog; Yog tias cov cua sov kub qis dhau lawm, lub zuag qhia tag nrho cov yas yuav tsis txaus, thiab thaum lub sij hawm tho / dov, sab hauv tsis zoo yog feem ntau yuav rub tawm.
• Tsis sib haum ntawm kev tho / dov tsis sib xws (txheej txheem seamless):  Thaum lub sij hawm oblique dov piercing, yog hais tias lub yob ceev yog siab dhau heev lawm thiab lub kaum sab xis pub me me, lub raj billet yuav raug rau ntau tshaj axial shear kev nyuaj siab, ua rau me me tsis xws luag yuav tsum tau rub sib nrug thiab txuas mus rau axial kev taw qhia, tsim ib txheej thaum uas tig mus rau lub raj phab ntsa; ntau dhau ib zaug- txo qis thiab hnav cov cuab yeej ntau dhau kuj tseem ua rau cov hlau tsis sib xws, ua rau muaj txheej txheej.
• Stress concentration nyob rau hauv txias dabtsi yog khoov txoj kev (vuam txheej txheem): Cov me me sab hauv uas twb muaj lawm nyob rau hauv lub sawb hlau yuav nthuav dav raws li thickness kev taw qhia nyob rau hauv lub rov khoov kev nyuaj siab thaum lub sij hawm txias dabtsi yog khoov txoj kev; Kev faib tawm tsis tsim nyog ntawm kev sib sau thiab ntau dhau ib zaug -dhau deformation kuj tseem yuav ua rau shear layering ncaj qha rau hauv cov kev taw qhia tuab.
• Ibtswj ncej-rolling cooling: Yog hais tias qhov txias txias yog ceev heev, nws yuav ua rau ib txhij ua kom muaj thermal stress thiab microstructure kev nyuaj siab, ua rau microcracks tsim nyob rau hauv lub central segregation cheeb tsam; Kev ua kom tsis zoo ntawm cov khoom txias thiab kev tsis sib haum xeeb ntxov yuav tiv thaiv kev ntxhov siab los ntawm kev tso tawm tag nrho, nws thiaj li txhim kho mus rau hauv macroscopic txheej.

Cov txheej txheem tsis xws luag yog tus yam ntxwv los ntawm nws qhov zais cia (feem ntau ntawm nws yog qhov tsis pom ntawm qhov muag liab qab) thiab nws qhov nthuav dav. Nws tsim nyog ua kom tsis muaj zog ntawm cov khoom siv yeeb nkab thiab ua rau muaj kev pheej hmoo loj rau kev ua tau zoo thiab kev nyab xeeb ntawm kev siv.

• Tseem ceeb deterioration ntawm mechanical zog: Txheej yuav ua rau cov kabmob phab ntsa tuab ntawm cov khoom siv yeeb nkab txo qis, thiab lub zog tensile nyob rau hauv cov txheej txheej yuav poob los ntawm 30% mus rau 50%, qhov cuam tshuam toughness tuaj yeem txo qis dua 10J, thiab cov yas (elongation) thiab qaug zog kuj yuav poob ib txhij; cov npoo ntawm cov txheej txheej yog cov ntsiab lus kev ntxhov siab ntawm ntuj tsim, thiab lawv yog cov nquag nthuav dav hauv kev quab yuam sab nraud.
• Kev ua tsis tiav ntawm cov txheej txheem kev ua haujlwm: Thaum lub sij hawm tom qab txias bending, expansion, flattening, thiab dabtsi yog khoov ua, cov txheej txheej yuav ncaj qha tawg; Yog tias muaj txheej txheej ntawm cov yeeb nkab kawg zawj, vuam yuav ua rau tsis tiav fusion thiab slag suav nrog thaum vuam, ncaj qha ua rau qhov tsis tsim nyog vuam sib koom ua ke.
• Ua tsis tau raws li qhov yuav tsum tau ua ntawm kev xeem: Thaum kuaj ultrasonic (UT) raws li cov qauv xws li GB / T 20490, txheej txheej yuav qhia pom tseeb tsis xws luag tsis xws luag, uas yog lub hauv paus tseem ceeb rau kev txiav txim siab tsis sib haum, ncaj qha ua rau cov khoom lag luam poob qis lossis scrapping.

• Tus qauv bearing fracture txaus ntshai: Thaum siv nyob rau hauv cov txheej txheem scenarios xws li lub tsev daim phiaj thiab cov neeg kho tshuab kev txhawb nqa, txheej nyob rau hauv zoo li qub loads yuav maj mam nthuav, ua rau seem tawg; nyob rau hauv alternating loads, nws yuav sai sai ua rau qaug zog tawg, ua rau tam sim ntawd brittle fractures thiab ua rau muaj kev ruaj ntseg yam ntxwv.
• Siab-cov kav dej xau thiab tawg: Thaum siv rau kev thauj mus los ntawm cov dej thiab cov kav dej siab, qhov nthuav dav ntawm txheej txheej ntawm phab ntsa sab hauv yuav ua rau cov yeeb nkab phab ntsa to. Nyob rau hauv siab - cov kev mob siab, nws tuaj yeem tawg ncaj qha; Yog tias thauj cov sulfur-muaj hydrogen lossis acidic media, cov txheej txheem txheej yuav ua rau hydrogen-induced cracking (HIC) thiab crevice corrosion, ua kom cov yeeb nkab tsis ua haujlwm.
• Durability thiab tsos deterioration: Tom qab cov corrosive nruab nrab nkag mus rau hauv cov txheej txheej, nws yuav ua rau sab hauv npog corrosion, maj mam rhuav tshem cov khoom siv yeeb nkab los ntawm sab hauv tawm, txo qhov kev pab cuam lub neej; txheej txheej hnyav kuj tseem yuav ua rau cov yeeb nkab saum npoo tuaj yeem, qhov sib txawv me me, thiab ua npuas thiab tev tawm tom qab galvanizing lossis txheej.

• Txhim kho lub purity ntawm molten steel thiab qhov zoo ntawm nruam casting:

1. Ntxiv dag zog rau LF / VD refining txheej txheem los xyuas kom meej lub sij hawm ntawm mos argon tshuab, txhawb lub flotation thiab tso tawm ntawm inclusions; siv cov tshuaj calcium los hloov kho Al₂O₃ nyuaj, hloov lawv mus rau hauv qhov qis qis - melting- cov ntsiab lus suav nrog, txo qhov chaw ntawm daim ntawv - zoo li stratification.
2. Siv cov pwm + kawg electromagnetic nplawm thoob plaws hauv cov txheej txheem nruam nruam los txo qhov nruab nrab kev sib cais thiab qhov nruab nrab porosity; tswj lub rub ceev tsis tu ncua kom tsis txhob yob slag thiab subsurface npuas.

• nruj me ntsis tshuaj xyuas cov ntaub ntawv raw thaum nkag mus rautusHoobkas: Rau billets / daim hlau nkag mus rau hauv lub Hoobkas, 100% ultrasonic ua ntej- kev tshuaj xyuas yuav tsum tau ua los xyuas kom pom cov stratification sab hauv, inclusions, thiab porosity defects. Cov ntawv tsis tsim nyog yuav tsum raug tsis lees txais ncaj qha; tib lub sijhawm, cov kab nrib pleb thiab nti yuav tsum tau muab tso rau hauv av kom tsis txhob muaj qhov txuas ntxiv ntawm qhov tsis xws luag thaum dov.

• Standardize billet cua sov npaj: Raws li cov hlau hom, tsim cov cua sov nkhaus nkhaus, tswj cov cua sov kom ntseeg tau tias cov cua sov nkag mus; npaj lub hauv paus chaw thau khoom ntawm billets ntawm tib lub specification thiab steel hom ua ntej kom tsis txhob muaj cua sov tsis sib xws vim qhov sib txawv loj.

• Precisely tswj cov txheej txheem cua sov: Xyuas kom lub sij hawm tuav ntawm seem sib npaug, tswj qhov kub ntawm qhov sib txawv ntawm lub raj seem nyob rau hauv qhov kev tso cai, tshem tawm "dual faces" thiab qis - kub dov; nruj me ntsis tswj lub sab sauv txwv ntawm cov cua kub kub kom tsis txhob muaj qhov txo qis hauv intergranular bonding quab yuam vim overheating.

• Optimize qhov tho thiab dov tsis tau (txheej txheem seamless):

1. Tswj cov yob ceev hauv qab qhov tseem ceeb txheej ceev, tsim nyog ua kom lub kaum sab xis pub, txo cov axial shear kev nyuaj siab thaum tho, thiab zam lub tiam ntawm txheej txheej los ntawm deformation mechanism.
2. Tsim nyog faib tus nqi txo ntawm txhua qhov dhau los kom tsis txhob deformation ntau dhau hauv ib qho dhau los; tsis tu ncua xyuas qhov hnav ntawm rolls, coj daim hlau, thiab lub taub hau, hloov lawv nyob rau hauv lub sij hawm yog tias qhov hnav tshaj qhov txwv, thiab xyuas kom meej cov hlau tsis sib xws.

• Optimize qhov txias khoov thiab vuam txheej txheem (vuam txheej txheem): Txhim kho cov txheej txheem dhau los, txo qhov ib zaug - dhau lub kaum sab xis deformation, txo qis kev ntxhov siab hauv cov kev taw qhia tuab, zam qhov nthuav dav ntawm sab hauv txheej ntawm cov sawb; phim lub siab - zaus vuam fais fab thiab extrusion npaum li cas los xyuas kom meej qhov weld fusion zoo, tsis txhob muab tso rau ntawm lub weld.

• Standardize ncej- dov txias thiab qeeb txias: 

1. Tswj cov ncej- dov txias ceev ntawm tus nqi ruaj khov ntawm 3 mus rau 5℃/ s, zam qhov tsim ntawm brittle bainite nyob rau hauv cov tub ntxhais ntawm tuab -walled billets, thiab txo cov koom haum kev nyuaj siab.
2. Ua haujlwm tas li- qhov kub thiab txias txias: rau qhov tuab tsawg dua lossis sib npaug li 50 hli, qhov txias txias yuav tsum siab dua lossis sib npaug li 12 teev; rau thicknesses> 50mm, qeeb txias yuav tsum siab tshaj los yog sib npaug rau 24 teev.Qhov pib kub ntawm pawg yuav tsum siab dua lossis sib npaug li 500 degree. Tsis txhob cia thaum ntxov unstacking; rau daim hlau uas muaj qhov ntev thiab dav zoo sib xws, muab lawv ua ke, thiab yog tias tsim nyog, qhwv lawv nrog asbestos daim ntaub rau rwb thaiv tsev kom tiv thaiv cov npoo kom txias sai heev. 

• Kev pov hwm tag nrho ntawm tsis yog - kev sim ua kom puas rau cov khoom tiav: Ua raws li GB / T 20490 tus qauv los ua qhov kev kuaj ultrasonic tsis siv neeg, npog tag nrho cov yeeb nkab phab ntsa ntawm 100%, kom pom qhov teeb meem cuam tshuam; ntxiv phau ntawv re- tshuaj xyuas qhov kawg ntawm cov yeeb nkab kom tsis txhob muaj cov khoom raug tso tawm.
• Kev kho cua sov thiab kev txheeb xyuas kev ua haujlwm: High-qib steel, tuab-walled square thiab rectangular raj nyob rau hauv normalizing + tempering kev kho mob kom tshem tawm cov residual kev nyuaj siab, homogenize tus qauv, thiab txhim kho kev sib cais rau toughness; cov qauv siab flattening, expansion, thiab txias dabtsi yog khoov txheej txheem kuaj kom paub tseeb tias tsis muaj layering cracking nyob rau hauv ua loads.
• Kev tsis raug traceability thiab kaw -loop txhim kho: Thaum kuaj pom muaj qhov tsis xws luag, thim rov qab cov txheej txheem steelmaking, casting, thiab dov txheej txheem raws li qhov tsis xws luag thiab kev faib tawm, txheeb xyuas qhov ua rau thiab kho cov txheej txheem tam sim; me me txheej txheej tuaj yeem muaj cov seem uas raug tshem tawm thiab txo qis rau kev siv, thaum txheej txheej hnyav ua rau tag nrho cov seem raug muab pov tseg.