Kev sib raug zoo ntawm vuam ceev thiab vuam zoo

Kev sib raug zoo ntawm vuam ceev thiab weld zoo yuav tsum to taub dialectically thiab tsis neglected. Feem ntau manifested nyob rau hauv lub cua sov theem thiab crystallization theem.

Thaum tshav kub kub: Nyob rau hauv cov xwm txheej ntawm high-frequency ncaj seam welded yeeb nkab, ntug ntawm cov yeeb nkab dawb paug yog rhuab los ntawm chav tsev kub mus rau lub vuam kub. Thaum lub sij hawm no, lub ntug ntawm cov yeeb nkab tsis muaj kev tiv thaiv thiab tag nrho raug rau huab cua, uas inevitably reacts hnyav nrog oxygen, nitrogen, thiab lwm yam nyob rau hauv cov huab cua, ua rau ib tug tseem ceeb nce nyob rau hauv nitrogen thiab oxides nyob rau hauv lub weld seam. Raws li kev ntsuas, cov ntsiab lus nitrogen nyob rau hauv weld seam nce 20-45 zaug, thiab cov ntsiab lus oxygen nce 7-35 zaug; Nyob rau tib lub sijhawm, cov ntsiab lus alloying xws li manganese thiab carbon uas muaj txiaj ntsig zoo rau lub vuam seam yog kub heev thiab evaporated, uas ua rau txo qis hauv cov khoom siv ntawm cov vuam seam. Los ntawm qhov no, nws tuaj yeem pom tias nyob rau hauv qhov kev txiav txim siab no, qhov qeeb ntawm vuam ceev, qhov tsis zoo ntawm qhov vuam seam yuav tsis zoo.

Tsis tas li ntawd, qhov ntev ntawm ntug ntawm cov rhuab billet raug rau saum huab cua, qhov qeeb ntawm vuam ceev, uas tuaj yeem ua rau tsim cov hlau tsis muaj hlau oxides hauv cov txheej sib sib zog nqus. Cov sib sib zog nqus-seated non-metallic oxides yog ib qho nyuaj rau kiag li nyem tawm ntawm lub weld seam thaum lub sij hawm tom ntej extrusion crystallization txheej txheem, thiab nyob twj ywm nyob rau hauv lub weld seam nyob rau hauv daim ntawv ntawm non-metallic inclusions tom qab crystallization, tsim ib tug kom meej meej fragile interface uas ua rau puas. continuity ntawm weld seam qauv thiab txo lub zog ntawm weld seam. Thiab qhov vuam ceev yog ceev, lub sij hawm oxidation yog luv, thiab cov uas tsis yog-hlau oxides uas tsim muaj kuj me me thiab txwv rau saum npoo. Nws yog ib qho yooj yim uas yuav tsum tau nyem tawm ntawm lub weld seam thaum lub sij hawm tom ntej extrusion txheej txheem, thiab yuav tsis muaj ntau heev uas tsis yog-metallic oxide residue nyob rau hauv lub weld seam, ua rau muaj zog weld.

Crystallization theem: Raws li cov hauv paus ntsiab lus ntawm metallurgy, thiaj li yuav tau txais cov welds muaj zog, nws yog ib qho tsim nyog yuav tsum ua kom zoo dua cov qauv ntawm cov welds kom ntau li ntau tau; Txoj hauv kev yooj yim rau kev ua kom zoo dua yog tsim kom muaj cov siv lead ua kom txaus nyob rau lub sijhawm luv luv, kom lawv tuaj yeem sib cuag nrog ib leeg ua ntej loj hlob thiab xaus cov txheej txheem crystallization. Qhov no yuav tsum tau ua kom lub vuam ceev kom sai sai tshem tawm cov vuam los ntawm qhov chaw cua sov, thiaj li yuav pab kom cov weld crystallize sai sai ntawm ib tug ntau dua ntawm undercooling; Thaum lub degree ntawm undercooling nce, tus nqi nucleation tuaj yeem nce ntau, thaum qhov kev loj hlob nce tsawg, yog li ua tiav lub hom phiaj ntawm kev ua kom zoo ntawm cov nplej loj ntawm cov weld seam. Yog li ntawd, txawm tias saib los ntawm cov cua sov theem ntawm cov txheej txheem vuam los yog qhov txias tom qab vuam, qhov ceev ntawm vuam ceev, qhov zoo ntawm cov vuam seam yog qhov zoo dua, muab qhov yooj yim welding tej yam kev mob.