Taw qhia
Thaum tsim cov khoom siv tshuaj lom neeg thiab roj av, txhawm rau txuag nqi npib tsib xee, hlau feem ntau welded rau npib tsib xee thiab alloys.
Cov teeb meem tseem ceeb ntawm vuam
Thaum vuam, cov khoom tseem ceeb hauv qhov vuam yog hlau thiab npib tsib xee, uas muaj peev xwm ntawm kev sib nrig sib solubility thiab tsis tsim cov sib txuas sib txuas. Feem ntau, cov ntsiab lus npib tsib xee hauv qhov vuam yog qhov siab, yog li nyob rau hauv fusion cheeb tsam ntawm cov welded sib koom, tsis muaj diffusion txheej yog tsim. Qhov teeb meem tseem ceeb ntawm vuam yog qhov nyiam tsim cov porosity thiab kub tawg hauv qhov vuam.
1.Porosity
Hlau thiab npib tsib xee thiab nws cov alloys thaum vuam, cov ntsiab lus tseem ceeb cuam tshuam rau kev tsim cov porosity hauv vuam yog oxygen, npib tsib xee thiab lwm yam alloying ntsiab.
① Cov nyhuv ntawm oxygen. Vuam, cov hlau ua kua yuav yaj ntau dua oxygen, thiab cov pa oxygen ntawm qhov kub thiab txias thiab npib tsib xee oxidation, tsim NiO, NiO tuaj yeem hnov mob nrog hydrogen thiab carbon nyob rau hauv cov kua hlau ua kom muaj dej vapor thiab carbon monoxide nyob rau hauv lub pas dej molten solidification, xws li lig dhau los khiav, residual nyob rau hauv lub weld ntawm tsim porosity. Nyob rau hauv cov ntshiab npib tsib xee thiab Q235-A submerged arc vuam ntawm hlau thiab npib tsib xee weld, nyob rau hauv cov ntaub ntawv ntawm nitrogen thiab hydrogen cov ntsiab lus tsis hloov ntau, qhov siab dua cov pa cov ntsiab lus nyob rau hauv lub weld, ntau dua cov pores nyob rau hauv lub weld.
② Cov nyhuv ntawm nickel. Nyob rau hauv cov hlau-nickel weld, solubility ntawm oxygen nyob rau hauv hlau thiab npib tsib xee yog sib txawv, solubility ntawm oxygen nyob rau hauv cov kua nickel yog ntau dua li nyob rau hauv kua hlau, thaum solubility ntawm oxygen nyob rau hauv cov khoom nickel yog me dua li nyob rau hauv cov khoom hlau, yog li ntawd, solubility ntawm oxygen nyob rau hauv lub nickel crystallization ntawm sudden hloov yog pronounced ntau tshaj li hais tias nyob rau hauv cov hlau crystallization. Yog li ntawd, qhov nyiam ntawm porosity nyob rau hauv lub weld thaum Ni yog 15% ~ 30% me me, thiab thaum Ni cov ntsiab lus loj, qhov kev nyiam ntawm porosity yog ntxiv mus rau 60% ~ 90%, thiab cov nyiaj yaj ntawm cov hlau yog khi kom txo qis, yog li ua rau lub siab ntawm kev tsim porosity los ua loj.
③ Kev cuam tshuam ntawm lwm yam alloying ntsiab. Thaum cov hlau-nickel weld muaj manganese, chromium, molybdenum, txhuas, titanium thiab lwm yam alloying ntsiab lus los yog nyob rau hauv txoj kab nrog cov alloying, yuav txhim khu lub weld anti-porosity, qhov no yog vim manganese, titanium thiab txhuas, thiab lwm yam muaj lub luag hauj lwm ntawm deoxygenation, thaum chromium thiab molybdenum los txhim kho cov hlau solubility. Yog li nickel thiab 1Cr18Ni9Ti stainless hlau weld anti-porosity tshaj npib tsib xee thiab Q235-A steel weld. Txhuas thiab titanium kuj tuaj yeem kho nitrogen hauv cov khoom sib txuas ruaj khov, uas tuaj yeem txhim kho qhov vuam los tiv thaiv porosity.
2. Kub tawg
Hlau thiab npib tsib xee thiab nws cov alloys nyob rau hauv weld, lub ntsiab yog vim li cas rau thermal cracking yog vim hais tias ntawm high nickel weld nrog dendritic lub koom haum, nyob rau hauv lub ntug ntawm coarse nplej, concentrated nyob rau hauv ib tug xov tooj ntawm tsawg melting point co-crystals, yog li tsis muaj zog kev sib txuas ntawm cov nplej, txo cov weld hlau tawg kuj. Tsis tas li ntawd, cov ntsiab lus npib tsib xee ntawm cov hlau weld yog siab dhau rau cov hlau weld los tsim cov thermal cracking muaj feem cuam tshuam rau cov hlau-nickel weld, oxygen, sulfur, phosphorus thiab lwm yam impurities ntawm lub vuam thermal cracking nyiam kuj muaj kev cuam tshuam zoo.
Thaum siv cov pa oxygen-dawb flux, vim qhov txo qis hauv qhov tsis zoo ntawm cov pa oxygen, sulfur, phosphorus thiab lwm yam tsis zoo hauv cov vuam, tshwj xeeb tshaj yog qhov txo qis hauv cov ntsiab lus oxygen, yog li ntawd cov nyiaj tawg tau txo qis heev. Vim hais tias lub pas dej molten crystallization, oxygen thiab npib tsib xee tuaj yeem tsim Ni + NiO eutectic, eutectic kub ntawm 1438 ℃, thiab cov pa oxygen tuaj yeem ntxiv dag zog rau cov teeb meem phom sij. Yog li thaum cov ntsiab lus ntawm cov pa oxygen nyob rau hauv lub vuam yog siab, qhov nyiam ntawm thermal cracking yog loj dua.
Mn, Cr, Mo, Ti, Nb thiab lwm yam alloying ntsiab, tuaj yeem txhim kho qhov tawg tsis kam ntawm cov hlau weld.Mn, Cr, Mo, Ti, Nb yog tus neeg sawv cev metamorphic, tuaj yeem kho lub koom haum weld, thiab tuaj yeem cuam tshuam cov kev taw qhia ntawm nws cov crystallization.Al, Ti kuj yog ib tug muaj zog deoxidizing tus neeg sawv cev, yuav txo tau cov pa oxygen nyob rau hauv lub weld.Mn muaj peev xwm ua kom muaj kev puas tsuaj rau lub koom haum refract. sulfur.
Mechanical zog ntawm welded pob qij txha
Cov khoom siv hluav taws xob ntawm cov hlau-nickel welding pob qij txha muaj feem xyuam nrog cov khoom siv hlau thiab cov khoom siv vuam. Thaum welding ntshiab npib tsib xee thiab cov pa roj carbon tsawg, thaum Ni sib npaug hauv cov vuam yog tsawg dua 30%, nyob rau hauv qhov txias txias ntawm cov vuam, cov qauv martensite yuav tshwm sim hauv cov vuam, ua rau cov yas thiab cov tawv tawv ntawm cov pob qij txha poob qis. Yog li ntawd, txhawm rau kom tau txais cov yas zoo dua thiab tawv tawv ntawm qhov sib koom ua ke, Ni sib npaug hauv cov hlau-nickel vuam yuav tsum ntau dua 30%
Lub sij hawm xa tuaj: Mar-10-2025