Titanium is a silver white transition metal with high specific strength and strong corrosion resistance, widely used in important fields such as aerospace, marine vessels, and petrochemicals. However, the high price of pure titanium has to some extent limited its application in civilian industry. Therefore, titanium is combined with ordinary steel plates to produce titanium/steel composite plates, which not only meet the requirements of strength but also have good corrosion resistance. Ti Fe compounds are easily formed at the interface of titanium/steel composite plates. Currently, there are two main methods to control the formation of Ti Fe brittle phases: one is to increase the intermediate layer, which reduces the diffusion of Fe atoms and lowers the formation of Ti Fe compounds; The second is to suppress the formation of Ti Fe compounds by controlling the generation of interface product TiC. Studies have shown that the order of free energy of interface compounds is TiFe>TiFe2>β - Ti>TiC, yog li TiC feem ntau yooj yim tsim ntawm lub interface. Tom qab ncav cuag qhov zoo tshaj plaws thickness ntawm qhov nruam thiab niaj hnub TiC txheej, nws yog qhov zoo los txhim kho lub zog sib txuas ntawm cov phaj sib xyaw, tab sis nws yog ib qho nyuaj rau kev tswj hwm hauv kev tsim khoom lag luam. Wu Jingyi et al. kawm txog cov teebmeem ntawm kev ntxiv cov ntaub ntawv sib txawv ntawm cov microstructure thiab cov khoom ntawm titanium/steel composite daim hlau, xws li Ni interlayer, Fe interlayer, Nb interlayer, thiab lwm yam. tau kawm tias nyob rau hauv qhov sib txawv ntawm qhov kub thiab txias, qhov sib cuam tshuam ntawm Ni interlayer tsis tsim TiC thiab TiFe brittle compounds ntawm 800 degree thiab 900 degree, nrog qhov nruab nrab shear zog ntawm 310 MPa thiab 224 MPa, feem. Xie et al. tau kawm txog cov nyhuv ntawm Nb interlayer ntawm lub interface ntawm titanium / steel puas daim hlau nyob rau hauv txawv dov kub tej yam kev mob. Txoj kev tshawb no qhia tau hais tias ntawm 800 degree thiab 900 degree, TiC thiab TiFe brittle compounds tsis tau tsim nyob rau hauv lub composite interface, thiab qhov nruab nrab shear zog mus txog 279 MPa.
Cov kev tshawb fawb saum toj no qhia tau hais tias ntxiv cov txheej txheem nruab nrab tuaj yeem cuam tshuam qhov cuam tshuam ntawm cov ntsiab lus cuam tshuam. Txawm li cas los xij, feem ntau ntawm cov kev tshawb fawb saum toj no yog ua raws li kev sim hauv kev sim, thiab cov khoom kim heev interlayer xws li Ni thiab Nb xaiv kuj txwv lawv cov ntawv thov kev lag luam. Txoj kev tshawb no tsom rau ntawm daim ntawv thov kev lag luam, siv SL3 ua cov txheej txheem los xyuas seb puas muaj cov khoom siv brazing tuaj yeem ua tiav thaum lub sij hawm dov cua sov txheej txheem, thiab tom qab ntawd los ntawm kev sib xyaw ua ke los txhim kho lub zog sib txuas ntawm cov phaj sib xyaw. Raws li cov kab ntau lawm ntawm lub tuam txhab, lub tshuab nqus tsev dov txheej txheem yog siv rau kev tshawb fawb, thiab cov teebmeem ntawm kev ntxiv electromagnetic ntshiab hlau DT4 thiab amorphous npib tsib xee raws li brazing cov ntaub ntawv SL3 ntawm lub microstructure thiab cov khoom ntawm titanium / steel composite daim hlau yog systematically kawm.
Txoj kev tshawb no tau txais kev sib koom ua ke ntawm billet thiab stacks cov billets raws li cov qauv ntawm "steel interlayer titanium isolation agent isolation agent titanium interlayer steel". Txoj kev sib xyaw dov no tuaj yeem tiv thaiv kev khoov deformation ntawm cov phaj sib xyaw thaum lub sij hawm dov txheej txheem thiab txhim kho cov kev ua tau zoo ntawm titanium / steel puas phaj. Lub spacer nrog lub thickness ntawm li ntawm 0.3 hli yog siv rau ntawm titanium (lub spacer yog tsim los ntawm cua sov thiab sib tov sib xyaw magnesium oxide, iav dej, thiab polyvinyl cawv) los tiv thaiv adhesion thaum dov. Plaub sab sealing vuam yog nqa tawm los ntawm submerged arc vuam, thiab ib lub qhov yog drilled ntawm ib kawg ntawm dov kev taw qhia. Lub tshuab nqus tsev twj tso kua mis thawj theem uas muaj lub tshuab twj tso kua mis thiab lub hauv paus twj tso kua mis yog siv rau lub tshuab nqus tsev, raws li qhia nyob rau hauv daim duab 1. Thaum lub tshuab nqus tsev degree nce mus txog rau hauv qab no 5 Pa, lub sealing yog nqa tawm, thiab thaum kawg nws raug xa mus rau lub steel mills. rau dov. Lub billet yog rhuab mus rau 880 degree nyob rau hauv lub desktop tsis kam rauv, tuav rau 4 teev, thiab dov 16 lub sij hawm ntawm ib tug dov kub ntawm (850 ± 10) degree, nrog ib tug tag nrho compression tus nqi ntawm txog 90%.
Sampling yog coj ntawm ntug ntawm qhov nruab nrab txoj hauj lwm ntawm lub billet, thiab raws li GB / T 6396-2008 tus qauv, cov khoom siv hluav taws xob ntawm cov khoom sib txuas tau raug sim siv qib 1 precision WAW-600 kW computer -controlled electronic universal kuaj tshuab. Kev ua haujlwm shear yog txiav txim siab los ntawm txoj kev nro shear. Cov qauv yog polished thiab polished. Lub sab steel yog thawj zaug corroded nrog 4% nitric acid cawv, thiab ces sab titanium corroded nrog ib tug sib tov ntawm hydrofluoric acid, nitric acid, thiab dej (2: 1:17). Cov qauv kev sib txuas tau pom zoo siv Axiolab5 (JX32) metallographic microscope, thiab qhov cuam tshuam thiab tawg ntawm cov phaj sib xyaw tau pom zoo siv Axia ChemiSEM LoVac scanning electron microscope, ua raws li kev tsom xam ntawm lub zog dispersive spectroscopy (EDS).
Mechanical zog
Table 2 qhia cov khoom siv ntawm cov khoom sib xyaw nrog cov interlayers sib txawv. Lub zog shear ntawm ob daim hlau sib xyaw yog ntau dua li 140 MPa teev hauv GB / T 8547-2019 tus qauv. Lub zog shear ntawm cov phaj sib xyaw nrog DT4 interlayer ncav cuag 187.4 MPa, thiab lub zog shear ntawm cov phaj sib xyaw nrog SL3 interlayer yog 148.6 MPa. Cov khoom siv nruab nrab interlayer tsis muaj qhov cuam tshuam loj rau lub zog tensile, thiab qhov cuam tshuam lub zog nqus tau ntau dua li 27 J teev hauv GB / T 700-2006 tus qauv. Qhov cuam tshuam nqus zog ntawm kev ntxiv DT4 interlayer composite board substrate yog me ntsis qis dua qhov ntxiv SL3 interlayer composite board. Ob hom phaj sib xyaw tau raug kuaj khoov (sab hauv khoov 180 degree, sab nrauv khoov 105 degree), thiab tsis pom muaj kab nrib pleb.
Microstructure
Daim duab 2 qhia txog microstructure ntawm kev sib txuas ntawm cov vaj huam sib luag nrog cov ntaub ntawv sib txawv. Daim duab 2 (a) qhia qhov sib txuas microstructure ntawm cov phaj sib xyaw nrog DT4 interlayer ntxiv. Cov qauv nplej ntawm lub hauv paus txheej yog strip-puab, feem ntau yog tsim los ntawm ferrite thiab pearlite. Txawm li cas los xij, cov nplej loj ntawm DT4 interlayer tsis sib npaug, tsuas yog qee cov nplej me me thiab cov nplej ntxhib yog ferrite. Lub plasticity thiab toughness yog tsis zoo, thiab nws yog feem ntau ua rau tawg nyob rau hauv shear quab yuam ntawm qhov chaw no. Daim duab 2 (b) qhia cov qauv kev sib txuas ntawm cov phaj sib xyaw nrog SL3 interlayer ntxiv. Lub hauv paus txheej yog tsim los ntawm pearlite thiab ferrite, nrog ib txheej decarburization nrog ib tug dav ntawm txog 5 0 μ m ntawm sab steel. Ib tug ntshiab grey dub diffusion band yog tsim nyob rau sab titanium, thiab cov qauv ntawm titanium sab nrog ib txoj kab uas hla ntawm txog 80 μ m yog pas nrig-puab. Vim tias Fe yog cov khoom ruaj khov ntawm - Ti, qhov kev sib cais ntawm Fe hauv Ti txo qhov kev hloov pauv ntawm eutectoid ntawm Ti, thiab - theem nucleates thiab loj hlob mus rau - theem thaum txias. Raws li Table 1, cov ntsiab lus carbon ntawm cov khoom siv sandwich SL3 yog qhov siab, ntawm 0.06%. Lub diffusion ntawm C lub ntsiab lus muaj feem ntau yuav tsim ib txheej TiC, thiab txheej TiC tuab dua yuav txo qhov kev sib txuas ntawm lub zog.
