Titanium thiab nws cov alloys hnov mob nrog oxygen thaum rhuab hauv huab cua lossis huab cua uas muaj oxygen. Thaum tshav kub qis dua 428 degree, ib qho kev tiv thaiv oxide zaj duab xis yog tsim. Raws li qhov kub thiab txias, lub thickness ntawm oxide zaj duab xis nce. Thaum qhov kub nce siab tshaj 538 degree, oxide zaj duab xis pib poob nws txoj kev tiv thaiv. Oxygen diffuses los ntawm cov yeeb yaj kiab mus rau sab hauv ntawm cov hlau, ua kom pom tseeb outgassing. txheej. Yog hais tias nws nce siab tshaj 815 degree, ib txheej ntawm xoob oxide nplai yuav tsim rau saum npoo ntawm titanium alloy.
Kev sib cuam tshuam ntawm hydrogen thiab titanium alloy muaj feem xyuam rau cov cua kub thiab lub sijhawm. Thaum nws qis dua 427 degree, yog tias muaj oxide zaj duab xis rau ntawm qhov chaw ntawm cov hlau, nws tuaj yeem tiv thaiv qhov nqus ntawm hydrogen. Thaum nws siab tshaj 427 degree, hydrogen pib nkag mus rau oxide txheej thiab nkag mus rau sab hauv ntawm cov qauv hlau. Qhov kev cuam tshuam ntawm hydrogen inhalation ntawm cov khoom ntawm titanium alloys kuj ncaj qha cuam tshuam rau lub xeev cov qauv ntawm cov hlau. Txij li thaum lub solubility ntawm hydrogen atoms nyob rau hauv lub theem yog ntau ntau dua li nyob rau hauv lub theem, tus nqi thiab cov duab ntawm cov theem ntawm cov alloy txiav txim hydrogen paug. ib qho ntawm cov ntsiab lus tseem ceeb.
Txhawm rau tiv thaiv titanium alloy los ntawm oxidizing, absorbing hydrogen thiab paug lwm yam kab mob thaum lub sij hawm superplastic forming, kev ntsuas yuav tsum tau coj los xyuas kom meej tias cov tsim titanium alloy qhov chaw muaj kev ua tau zoo heev.
Tam sim no, cov kev ntsuas tseem ceeb yog: txheej tiv thaiv, nqus cua sov thiab inert gas (argon) tiv thaiv.
1. Txheej txheej tiv thaiv
Tom qab qhov saum npoo ntawm qhov tsim dawb huv yog ntxuav, ib qho kev tiv thaiv txheej ntawm ib qho thickness yog siv. Tom qab cov khoom raug demoulded, txheej yog tshem tawm los ntawm alkali ntxuav, pickling los yog xuab zeb tshuab.
Coatings yuav tsum muaj cov khoom tseem ceeb hauv qab no:
a. Kev kub siab ua haujlwm, tuaj yeem siv rau qhov kub thiab txias ntawm 750-1050 degree ;
b. Nws yuav tsum muaj cov nyhuv lubrication los tiv thaiv qhov khoob ntawm qhov raug khawb thaum tsim;
c. Cov txheej tuaj yeem ua raws li qhov chaw ntawm qhov khoob ntawm qhov ua haujlwm kub;
d. Yooj yim tshem tawm tom qab cua sov;
e. Tsis muaj teeb meem tshuaj, tsis muaj kuab paug rau ib puag ncig thiab tsis muaj kev puas tsuaj rau tib neeg kev noj qab haus huv.
2. Lub tshuab nqus tsev tsim
Rau -type titanium alloys nrog nyias phab ntsa thickness, siab saum npoo ci yuav tsum thiab muaj zog susceptibility rau hydrogen embrittlement, lub tshuab nqus tsev tsim yog qhov zoo tshaj plaws.
Kev tsim lub tshuab nqus tsev tsis tas yuav tsum tau siv cov khoom siv hluav taws xob kim kim. Ntev npaum li qhov chaw kaw tau tsim los ntawm qhov khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khawm mus rau qhov tsim kub, qhov degree ntawm kev sib cuag ntawm sab sauv thiab sab kab noj hniav ntawm cov pwm yuav tsum tau tswj kom ua tiav lub nqus tsev kawm ntawv ntawm 10^(-3) Torr los yog saum toj no, lub hom phiaj tsim ua tiav los ntawm kev hloov cov kav dej. valve thaum tsim thiab sau nrog argon roj. Txoj kev no yog siv nyob rau hauv titanium ntawv ci corrugated phaj tsim thiab txaus siab tau tiav. Thaum lub tshuab nqus tsev kawm ntawv tswj ntawm 10^(-3) Torr, cov ntsiab lus hydrogen qis dua li qhov yuav tsum tau ua. Thaum lub tshuab nqus tsev kawm ntawv nce mus txog 10^(-5) Torr, qhov chaw uas ci ntsa iab tuaj yeem tau txais.
