Titanium thiab titanium alloys muaj kev tiv thaiv nruj heev thaum vuam. Thaum cov ntsiab lus carbon ntawm cov vuam yog 0.55 feem pua, cov yas ntawm cov vuam yuav luag ploj mus thiab dhau los ua cov khoom siv tawv heev, thiab qhov brittleness tsis tuaj yeem tshem tawm los ntawm kev kho cua sov tom qab vuam.
Muaj ntau cov ntsiab lus hauv titanium alloys, uas muaj kev cuam tshuam rau lub cev ntawm titanium. Ntawm lawv, carbon yog ib qho impurity nyob rau hauv titanium thiab titanium alloys. Thaum cov ntsiab lus carbon qis dua 0.13 feem pua, carbon yog nyob rau hauv alpha titanium, thiab cov kev txwv ntawm weld lub zog yog me ntsis txwv. Nce, lub plasticity yog me ntsis txo, tab sis tsis muaj zog npaum li cov nyhuv ntawm oxygen thiab nitrogen. Txawm li cas los xij, thaum cov ntsiab lus carbon ntawm cov welding tau nce ntxiv, tus naj npawb ntawm reticulated TiC nyob rau hauv lub weld nce nrog qhov nce ntawm cov ntsiab lus carbon, yog li ntawd cov plasticity ntawm weld txo qis sharply, thiab cov kab nrib pleb yuav tshwm sim nyob rau hauv qhov kev txiav txim. vuam kev nyuaj siab.
Lub vuam seam tsis xws luag ntawm titanium raj yog vim lub fact tias argon roj tiv thaiv txheej tsim los ntawm argon arc vuam teeb tuaj yeem tsuas yog tiv thaiv lub pas dej ua ke los ntawm cov teeb meem ntawm huab cua thaum lub titanium raj yog welded.
Txawm li cas los xij, nws tsis muaj kev tiv thaiv zoo ntawm cov welded seam thiab nws cov cheeb tsam ib puag ncig uas tau ruaj khov thiab nyob rau hauv qhov kub thiab txias, thiab titanium raj vuam nyob rau hauv lub xeev no thiab nws cov cheeb tsam ib puag ncig tseem muaj peev xwm nqus nitrogen thiab oxygen hauv lub xeev. huab cua. .
Oxygen yog absorbed los ntawm 400 degree, nitrogen yog absorbed los ntawm 600 degree, thiab huab cua muaj ib tug loj npaum li cas ntawm nitrogen thiab oxygen. Nrog rau qhov maj mam nce ntawm qib oxidation, xim ntawm titanium raj weld hloov thiab plasticity ntawm weld txo.
Silvery dawb (tsis muaj oxidation) golden daj (TiO, titanium pib nqus hydrogen ntawm li 250 degree . Me ntsis oxidized) xiav (me ntsis oxidized los ntawm Ti2O3) grey (hnyav oxidized los ntawm TiO2).
1. Cov nyhuv ntawm carbon
Titanium thiab titanium alloys kuj ruaj khov thaum vuam, tab sis nyob rau hauv chav tsev kub. Cov kua dej thiab cov pas dej molten hlau muaj zog nqus ntawm hydrogen, oxygen, thiab nitrogen, thiab nyob rau hauv lub xeev cov khoom, cov gases tau cuam tshuam nrog lawv.
Raws li qhov kub thiab txias, lub peev xwm ntawm titanium thiab titanium alloys nqus hydrogen, oxygen thiab nitrogen kuj nce ntxiv. Titanium pib nqus hydrogen ntawm 250 degree, oxygen los ntawm 400 degree, thiab nitrogen los ntawm 600 degree. Tom qab cov roj tau absorbed, nws yuav ncaj qha ua rau embrittlement ntawm welded sib koom, uas yog ib qho tseem ceeb heev cuam tshuam rau lub vuam zoo.
2. Hydrogen yog cov nyhuv
Qhov laj thawj tseem ceeb yog vim qhov nce ntawm cov ntsiab lus hydrogen, hydrogen yog qhov tseem ceeb tshaj plaws cuam tshuam rau cov khoom siv ntawm titanium hauv cov pa roj impurities. Kev hloov pauv ntawm cov ntsiab lus hydrogen ntawm cov weld muaj qhov cuam tshuam loj tshaj plaws ntawm cov khoom siv ntawm cov vuam.
Lub flaky los yog koob zoo li TiH2 precipitated nyob rau hauv lub weld nce. Lub zog ntawm TiH2 yog qhov tsawg heev, yog li cov flaky lossis rab koob zoo li HiH2 ua raws li qhov kev txiav txim siab, thiab kev sib koom ua ke kev ua tau zoo yog txo qis; qhov kev hloov pauv ntawm cov ntsiab lus hydrogen ntawm lub vuam muaj qhov cuam tshuam rau lub zog.
