Vuam yog ib qho kev siv thev naus laus zis uas ua tiav kev sib txuas ntawm atomic ntawm qhov chaw ntawm ob lossis ntau qhov chaw ua haujlwm sib cais los ntawm kev siv cua sov, kev thov siab, lossis kev sib xyaw ntawm ob qho tib si, ntxiv los ntawm cov ntaub ntawv muab tub lim. Raws li ib feem tseem ceeb ntawm cov tshuab siv hnyav, qhov zoo ntawm vuam booms yog ncaj qha ntsig txog kev nyab xeeb ntawm tag nrho lub tshuab. Tsis zoo li kev sib txuas ntawm cov tshuab, vuam tsim ib daim ntawv cog lus metallurgical, nws cov xwm txheej tseem ceeb suav nrog lub zog, ib puag ncig, thiab kev sib koom ua ke. Raws li lub zog qhov chaw, vuam tuaj yeem muab faib ua peb pawg: fusion vuam, siab vuam, thiab brazing. Ntawm lawv, fusion vuam yog feem ntau siv hauvwelding boom manufacturing, accounting rau ntau tshaj 90% ntawm cov ntawv thov kev lag luam.
I. Welding Metallurgy Principles and Material Selection for Welding Booms
Vuam metallurgy yog ib txoj kev xav tseem ceeb uas kawm txog cov cai ntawm kev tsim cov pas dej molten, solidification, theem transformation, thiab tshuaj muaj pes tsawg leeg hloov thaum lub sij hawm vuam, thiab plays lub luag hauj lwm txiav txim siab nyob rau hauv kev ua tau zoo ntawm vuam booms. Lub pas dej molten ntawm vuam booms yog tus cwj pwm los ntawm qhov ntim me me, qhov kub thiab txias, lub sijhawm luv luv, thiab ceev ceev txias, ua rau cov txheej txheem crystallization sai. Lub solidification ntawm weld hlau yog raws li nyob rau hauv unmolten puag hlau nplej nyob rau hauv lub fusion cheeb tsam thiab loj hlob raws lub tshav kub dissipation kev taw qhia, tsim ntau yam crystallization morphologies los ntawm planar nplej mus rau columnar nplej. Lub tshav kub- cuam tshuam cheeb tsam (HAZ) yog thaj tsam ntawm lub hauv paus hlau cuam tshuam los ntawm vuam cua sov tab sis tsis yaj. Nws cov kev hloov pauv microstructural yog sib koom ua ke los ntawm cov cua kub thiab cua txias, ua rau ntau thaj tsam xws li fusion zone, overheated zone, thiab normalizing zone.
Vuam booms feem ntau yog ua los ntawm qis- alloy siab - lub zog hlau, xws li BS700MCK2 siab- lub zog phaj, uas muaj lub zog tawm los ntawm ntau dua lossis sib npaug rau 700MPa thiab zoo heev weldability, txias formability, thiab qis- kub cuam tshuam toughness. Cov khoom siv no yog ib qho qis-carbon low- alloy structural steel, uas tau txais kev vuam zoo heev los ntawm kev txo cov pa roj carbon sib npaug thiab weld tawg rhiab heev index. Thaum lub sij hawm vuam txheej txheem ntawmvuam booms, cov tshuaj tiv thaiv kab mob xws li oxidation, txo, thiab nitridation tshwm sim ntawm lub pas dej molten hlau thiab ib puag ncig nruab nrab. Nws yog ib qho tsim nyog los xyuas kom meej qhov tsim nyog tshuaj muaj pes tsawg leeg ntawm weld thiab zam qhov tsis xws luag los ntawm cov khoom siv vuam tsim nyog thiab kev tswj cov txheej txheem.
II. Influence Law of Welding Thermal Process on Welding Boom Quality
Cov txheej txheem vuam thermal yog qhov chaw ntawm vuam metallurgical cov tshuaj tiv thaiv, microstructural transformations, thiab kev ntxhov siab deformation. Hauv - kev kawm tob txog cov cai ntawm kev tsim hluav taws xob, kev hloov pauv, thiab kev tawg yog qhov tseem ceeb rau kev txhim kho qhov zoo ntawm vuam booms. Cov txheej txheem vuam sib txawv muaj qhov sib txawv tseem ceeb hauv cov yam ntxwv ntawm cov khoom siv hluav taws xob: cov hlau thaiv hlau arc vuam muaj lub zog tsis tshua muaj zog, tawg tawg tawg, thiab tshav kub loj - cuam tshuam cheeb tsam; thaum laser vuam thiab plasma arc vuam muaj lub zog muaj zog thiab muaj cua sov me me- thaj tsam cuam tshuam.
Vuam cov khoom siv hluav taws xob yog hais txog cov cua sov uas tau txais hauv ib chav tsev ntev ntawm qhov vuam, xam los ntawm cov mis E=60IU/(vη), qhov kuv yog qhov vuam tam sim no, U yog qhov vuam voltage, v yog qhov vuam ceev, thiab η yog qhov thermal efficiency. Thaum lub sij hawm welding txheej txheem ntawm welding booms, overheat input yuav ua rau kom lub ncov kub, qeeb tus nqi cua txias, nthuav lub tshav kub- cuam tshuam cheeb tsam, thiab coarsen nplej, yog li txo toughness; Cov cua kub tsis txaus yuav ua kom cov cua txias kom nrawm, yooj yim ua rau cov txheej txheem tawv tawv thiab cov kab nrib pleb txias.
Hauv kev tsim khoom ntawmvuam booms, nws yog ib qho tsim nyog los tswj qhov kub ntawm qhov sib cuam tshuam thiab txais yuav tsum tsim nyog preheating thiab post- cov txheej txheem cua sov. Rau cov phaj tuab tuab, preheating yuav tsum tau ua kom them nyiaj rau qhov kub poob qis thiab tiv thaiv cov kab mob khaub thuas. Lub vuam ib puag ncig kuj xav tau kev tswj xyuas nruj, suav nrog cov kev cai xws li kev siv lub teeb ci hauv qhov chaw ua haujlwm, cua ceev hauv qab 2m / s, thiab av noo qis dua 60%.
III. Welding Defect Control thiab Vuam Boom Performance Guarantee Strategies
Vuam tsis xws luag yog qhov tseem ceeb tshwm sim tawm ntawm - ntawm - tswj cov txheej txheem metallurgical lossis cov txheej txheem thermal tsis sib npaug. Feem ntau qhov tsis xws ntawm vuam booms muaj xws li porosity, slag suav nrog, tawg, thiab undercut. Porosity yog qhov tsim thaum cov roj yaj hauv lub pas dej molten tsis khiav tawm thaum lub sijhawm txias thiab khov kho, thaum cov slag suav nrog los ntawm oxides thiab sulfides tsim los ntawm cov tshuaj tiv thaiv metallurgical uas tsis ntab mus rau saum npoo ntawm lub pas dej molten raws sijhawm.
Cov kab nrib pleb tau muab faib ua ob pawg: kub tawg thiab cov kab nrib pleb txias. Cov kab tawg kub yog tshwm sim los ntawm kev tsim cov yeeb yaj kiab ua kua vim qhov ua kom muaj zog ntawm qis - melting - cov ntsiab lus ntawm cov ciam teb nplej thiab tawg nyob rau hauv vuam kev nyuaj siab; Cov kab nrib pleb txias yog tsim los ntawm kev tsim cov txheej txheem tawv tawv uas tshwm sim los ntawm cov cua txias ntau dhau thiab sib sau ntawm diffusible hydrogen. Los xyuas kom meej qhov kev cia siab ntawm kev ua haujlwm ntawmvuam booms, nws yog ib qho tsim nyog yuav tsum tau soj ntsuam cov cuab yeej cuab tam ntawm cov pob qij txha, suav nrog lub zog, toughness, plasticity, thiab hardness.
Ib qho kev sib txuas welded muaj peb ntu: weld hlau, fusion zone, thiab tshav kub- thaj tsam cuam tshuam, thiab nws qhov kev ua tau zoo tag nrho yog qhov kev xav ntawm peb. Lub fusion zone yog qhov tsis muaj zog ntawm qhov sib koom ua ke, uas yog qhov yooj yim los ua qhov chaw pib tawg vim yog cov qauv tsis sib xws thiab cov nplej ntxhib. Los ntawm kev siv cov txheej txheem vuam tsim nyog thiab cov txheej txheem tsis zoo, xws li cov txheej txheem ua kom zoo ntawm kev siv tsib -section backstep welding rau hauv paus vuam thiab ob-section central symmetry welding rau capping welding, welding residual stress thiab deformation yuav txo tau zoo. Nrog rau kev vam meej, kev tsim khoom thiab cov khoom lag luam zoo ruaj khov ntawm vuam booms yuav zoo heev.
