Rnaea 20. 06pa6oTKa nopowKOBblX M3AenMM 


Мы поможем в написании ваших работ!



ЗНАЕТЕ ЛИ ВЫ?

Rnaea 20. 06pa6oTKa nopowKOBblX M3AenMM



 

Tpe6oBaHHSI, npe,llbSIBJISieMhie K MexaHHqecKHM H $HJHKO-XHMH­ qecKHM CBOHCTBaM nopOllIKOBhlX H3.IJ.eJIHH, HenpepblBHO B03paCTaIOT. IlOBhlCHTh cooTBeTCTByIOIUHe CBOHCTBa nopOllIKOBhlX MarepHaJIOB MO)l(­ HO H3MeHeHHeM HX CTJ>YKTYPhl, pa3JJHqHblMH BH,llaMH TepMHqecKOH, XHMHKO-TepMHqeCKOH, TepMOMexaHHqecKOH H,llHCnepCHOHHo-ynpoq­ HSIIOIUeH o6pa6oTKH, JaIUHTOH OT KOpp03HH H MeXaHHqeCKOH o6pa-

60TKOH,llJISI npH,llaHHSI H3.IJ.eJIHSIM Tpe6yeMhlX pa3MepoB H <t>opMhl.

 

TepMM'lecKaJI o6pa6oTKa

 

Ilo,ll TepMHqeCKOH o6pa60TKOH (TO) noHHMaeTCSI COBOKYnHOCTh onepaUHH HarpeBa, Bh,llep)l(KH npH BhlCOKHX TeMnepaTYPaX H OXJia)l(­

,lleHHSI c pa3JIHqHQH CKOpOCThlO c ueJibIO H3MeHeHHSI CTJ>YKTYPhl H o6pa6aTbIBaeMOCTH MaTepHana, ynyqllleHHSI KOM6HHaUHH ero Mexa­ HHqecKHX H $HJHqecKHX CBOHCTB.IlpaKTHKa noKa3hIBaeT, qro TaKOMY B03,lleHCTBHIO MOryT H,llOJI)l(Hbl nO,llBepraThCSI MHOrHe nopOllIKOBbie H3.IJ.eJIHSI paJJiffqHOfO HaJHaqeHHSI, B nepByIO oqepe,llb KOHCTpYKUHOH­ Hb e Ha)l(eJieJHOH ocHoBe. BoJMO)l(HOCTh npHMeHeHHSI TO 06yc110BJie­ Ha TeM, qTo Ka)((,llaSI qacTHUa MeTaJIJIHqeCKOH OCHOBhl nopOllIKOBOfO MarepHaJia npe.IJ.CTaBJISleT co6oi{ KOMnaKTHhlH MHKpOCJIHTOK, B KOTO­ poM npH HarpeBe H OXJia)((,lleHHH npOHCXO,llSIT TaKHe)Ke npeBpame­ HHSI, KaK H B 60JihllIHX o6beMax KOBaHoro HJIH JIHTOfO CnJiaBa. 0,llHaKO CYIUeCTBeHHOe OTJIHqHe CTpYKTYPhInopOllIKOBOfO MaTepHaJia OT CTpYK­ TYPhlMaTepHana, nonyqeHHoro no Tpa.IJ.HUHOHHhIM TexHonorHsi:M, He noJBOJISieT aBTOMaTHqeCKH nepeHOCHTh JaKOHOMepHOCTH TenJIOBh X npoueccoB B KOMnaKTHOM MaTepHane Ha nopOllIKOBhlH.

06Jia,llaSI 60JibllleH cyMMapHOH noeepXHOCThIO, nopHCTbie nopolll­ KOBble H3,lleJIHSI npH HarpeBaHHH 6onee CKJIOHHhl K 06e3yrnepO)l(HBa­ HHIO, OKHCJieHHIO H T.,ll., no3TOMY npH HX o6pa60TKe Heo6XO,llHMO

npHMeHSITh JIH60 6onee 6bICTphlH HarpeB, npH KOTOpOM Ja cqeT MeHh­ lllero BpeMeHH TenJIOBOfO B03,lleHCTBHSI XHMHqecKoe B3aHMO.IJ.eHCTBHe JaTparHBaeT MeHhllIHe o6beMhI, JIH6o ocymecTBJISITh ttarpeB B JaIUHT­ Hh X (HeHTpaJihHh X, BOCCTaHOBHTeJibHhlX) aTMoc<t>epax HJIH B yrne­ po.nco,llep)l(aIUHX JachmKax. Han11q11e B nopollIKOBh X MaTepHanax nop, JanoJIHeHHh X raJOM, cymecTBeHHO CHH)l(aeT Ten110- H TeMnepaTYpO­ npOBO.IJ.HOCTh HJ,lleJIHH. B CBSIJH c 3THM npH npoq11x paBHh X yc110BHS1X HX CKOpOCTH HarpeBa H OXJia)((,lleHHSI, a TaK)l(e.npyrne xapaKTepHCTH-


KH npou;eccoB TO 6y.nyr OTJIH'.J.aTbCH OT aHaJIOfH'IHb X noKaJaTeJieH:

.lI)IH 6ecnopHCTb X HJ,lleJIHH.

113-Ja 6oJiee HHJKHX TenJioQ>HJHlJeCKHX H npO'IHOCTHblX (B oco- 6eHHOCTH.llHHaMHlJeCKHX) CBOHCTB nopOllIKOBb e HJ,lleJIHH BeCbMa 'IYBCTBHTeJibHb lK TenJIOBb M y,napaM. nopbl,HBJIHHCb KOHLI;eHTpaTOpa­ MH HanpH.>KeHHH, npH peJKOM OXJia.>K,lleHHH Bb JbIBaIOT noHBJieHHe JHa'IHTeJibHb X HepaBHOMepHo pacnpe.neJieHHblX TepMHlJeCKHX H Q>a­ JOBb X Hanp.H.>KeHHH, npHBO,llHlllHX K HJMeHeHHIO CTpyKTypbl MaTepH­ aJia, a TaK.>Ke K nOHBJieHHIO TpelllHH.

BJIHHHHe oco6eHHOCTeH: CTpYKTYPhl nopollIKOBb X MaTepHaJIOB Ha npou;eCCbl HX repMH'leCKOH o6pa60TKH K HaCTOHllleMy BpeMeHH HaH- 6oJiee noJIHO HJyqeHo.llllH CHCTeMbIFe-C c paJJIH'IHb MH nernpyio­ lllHMH 3JieMeHTaMH, T.e..lI)IH CTaJieH, nonyqeHHb X KaK HJ CMeceH: no­ pOllIKOB HCXO,llHblX KOMnOHeHTOB, TaK H HJ npe.nBapHTeJibHO JierHpo­ BaHHblX nopOllIKOB. 3TO CBHJaHO c TeM, 'ITO.lI)IH CTaJieH, nonyqeHHb X no Tpa,llHLI;HOHHOH TeXHOJIOfHH, HaKonJieH orpoMHblH reopeTHlJeC­ KHH H 3KcnepHMeHTaJibHblH MaTepHaJI, H c TeM, 'ITO HJ,neJIHH Ha xe­ JieJHOH OCHOBe COCTaBJIHIOT 60JibllIYIO lJaCTb TOHHa.>Ka nopOllIKOBOH

MeTaJIJiyprHH.

B xo.ne MHOro'IHCJieHHb X HCCJie,noBaHHH o6HapyxeHo, 11To noBbI­ llleHHa».neQ>eKTHOCTb nopOllIKOBb X CTaJieH, HeO,UHOPO.UHOCTb pacnpe­

.ueneHHH yrnepo.ua H.upyrnx 3JieMeHTOB no o6'beMy JaroTOBKH, 6oJib­ llla.H CYMMapHaH noBepxHOCTb cymecTBeHHO HJMeHHIOT TepMo,UHHa­ MH'leCKoe COCTOHHHe MaTepHaJia, YBeJIHlJHBaH Janae CB060.UHOH 3Hep­ fHH H CHH.>KaH pa6ory o6paJoBaHH.H JaPO.UblllleH HOBOH Q>aJbl. B pe­

JYJibTaTe.uaxe He60JibllIOH npHTOK TenJIOBOH 3HeprnH npH neperpeBe


pHTa H u;eMeHTHTa.

.Hccne,aoBaHH» pacna.na nepeoXJia.>K,neHHoro aycreHHTa B HJoTep­ MH'leCKHX YCJIOBHHX H npH HenpepbIBHOM OXJia.>K,lleHHH noKaJaJIH, 'ITO OCHOBHb e JaKOHOMepHOCTH 3TOfO npou;ecca B nopollIKOBb X CTaJIHX aHaJIOfH'IHbl JaKOHOMepHOCTHM B KOBaHb X H JIHTb X CTaJI.HX, O,UHaKO

oco6eHHOCTH nepBblX OKaJblBaIOT BJIH.HHHe KaK Ha KHHeTHKY npou;ec­

 

ca, TaK H Ha TeMneparypy, HHKY6au;HOHHb U nepHO.U H o6mee BpeMH npeBpameHHH. c yBeJIHlJeHHeM nopHCTOCTH B yrnepo,UHCTb X nopolll­

KOBb X CTaJIHX 3TO BpeMH YMeHblllaeTCH.,[(HcnepCHOCTb HCXO.UHbIX no­ pOllIKOB OKaJblBaeT TaKOe.>Ke BJIH.HHHe, HO B MeHbllleU CTeneHH, lJeM nopHCTOCTb.

B cnyqae MapreHCHTHoro npeBpameHH» TaK.>Ke Ha6n10.uaeTc» aHa­

JIOfHH npou;eccoB B JIHTb X H nopollIKOBblX CTaJIHX, O,UHaKO CTpYKTYP­ Hb e oco6eHHOCTH nocJie,UHHX o6yCJIOBJIHBaIOT HHb e.UBH.>KYlllHe CHJibl. 06JiaCTH, o6e,aHeHHb e yrnepo,UOM, HMeIOmHe nOBblllleHttyIO.ueQ>eKT­ HOCTb H co.uepxamHe MHKpOBKJIIOlJeHH.H, MOryr CJiyxHTb u;eHTpaMH

HalJaJia 3TOfO npeBpameHHH, KOTOpoe HalJHHaeTCH npH 6onee Bb CO­ KOH TeMneparype (TOlJKa MJ, lJeM npH COOTBeTCTBYIOllleM cpe,aHeM

co.uep.>KaHHH yrnepo.ua. TaKHM o6paJoM, noBb llleHHe nopHCTOCTH H CBHJaHHOe c 3THM ycJio.>KHeHHe CTpYKTYPHOfO COCTOjj:HH.H npHBO.UHT K

noBbillleHHIO TO'IKH MH (pHC. 275), o,aHaKo npH 3TOM na.naeT TBep­

.uocTb MapTeHCHTa HJ-Ja caMOOTnyCKa npH OXJia.>K,lleHHH.uo KOMHaT­ HOH reMneparypbI.

TepMH'lecKaH o6pa6oTKa nopollIKOBb X MaTepHaJIOB.ueJIHTCH Ha

npe.uBapHTeJibHYIO (paJJIHlJHb e BH,Ubl OT.>KHra H HOPMaJIHJau;HH) H OKOH'laTeJibffYIO (JaKaJIKa c omycKoM). B HeKoTOpb X CJiyqaHx oT.>KHr H


A
Ha,n TO'IKOH


npHBO.UHT K BOJHHKHOBeHHIO Japo,ab llleii aycTeHHTa.


HOpMaJIHJau;HH Moryr 6b Tb oKoH'laTeJibHOH TO.


Eme O.UHOH npH'IHHOH noHH.>KeHHH reMneparypbIHa11aJia aycTeHHT­ Horo npeBpameHHH MO.>KHO ClJHTaTb HeO,UHOPO.UHOCTb CTpYKTypblCTa­ JieH no BeJIH'IHHe JepHa. B CBHJH c TeM, 'ITO HJ-Ja HaJIHlJHH HCXO,UHb X

Me.>K'laCTHlJHb X rpaHHU pOCT JepHa npH cneKaHHH MO.>KeT orpaHHlJH­ BaTbCH o6'beMaMH 3THX CaMb X lJaCTHU,B nopOllIKOBb X CTaJIHX Hap.H,Uy c KpynHb MH JepHaMH, BOJHHKllIHMH B peJyJibTaTe Me.>K11acTH'IHOH peKpHCTaJIJIHJau;HH, MOryr npHCYfCTBOBaTb H MeJIKHe, Ha rpaHHu;ax KOTOpb X HJ-Ja MaJIOfO paCCTOHHHH.UHQ>Q>yJHH yrnepo.ua 6b CTpee.no­ CTHraeTCH KpHTH'leCKaH ero KOHLI;eHTpau;HH, 'ITO HHTeHCHQ>Hu;HpyeT nepJIHTo-aycTeHHTHoe npeBpameHHe. KpoMe Toro, HaJIH'IHe Me.>K'lac­ TH'IHb X rpaHHU npH 60JibllIOU XHMHlJeCKOH HeO,UHOpO,UHOCTH o6yc­

JIOBJIHBaeT OTJIHlJHe CTpYKTypHoro COCTaBa nopOllIKOBOH CTaJIH OT aHaJIOrH'IHou JIHTOH. HanpHMep, B CTaJIH c 0,8% yrnepo.ua (3BTeKTO­ H,UHou) KpOMe nepJIHTa OTMe11aeTCH npHCYfCTBHe HJ6bITO'IHb X Q>ep-

 


npe,UBapHTeJlbHaH o6pa60TKa npOBO,UHTCH KaK Ha nopOllIKaX, TaK H Ha cQ>opMoBaHHb X, cne11eHHbIX H OTKaJIH6poBaHHblX JafOTOBKax c u;eJibIO yJiyqllleHHH HX CTpYKTYPbl, TeXHOJIOfHlJeCKHX H MexaHHlJeCKHX CBOUCTB (CHH.>KeHHH TBep,UOCTH, yJiyqllleHHH o6pa6aTbIBaeMOCTH pe­ JaHHeM, yMeHbllleHHH H noJIHOfO CHHTH.H OCTaTOlJHb X Hanp.H.>KeHHH). 0KOHlJaTeJibHOU o6pa60TKe o6b 'IHO no,UBepraIOT fOTOBb e HJ,UeJIHH c u;eJibIO yJiyqllleHHH HJIH Q>opMHpOBaHHH Ja,llaHHOH CTpYKTYPblH npH­

.uaHHH Heo6xo.UHMbIX cBoucTB.

nopOllIKOBbie CTaJIH MOfYT no,aBepraTbCH paJJIHlJHb M BH,UaM OT­

.>KHra: noJIHOMy, HenoJIHOMy, HHJKOMy, peKpHCTaJIJIHJaLI;HOHHOMY H

.UHQ>Q>yJHOHHOMy. HHJKHU OT.>KHf npHMeHHIOT TOJlbKO.lI)IH noHH.>Ke­

HHH TBep,UOCTH, HenoJIHb H -.lI)IH noHH.>KeHH.H TBep,UOCTH, yJiyqllle-

. HH.H 06pa6aTb1BaeMOCTH H nOBb llleHH.H BHJKOCTH CTaJIH 6eJ HJMeJib­

lJeHH.H JepHa. noJIHb U OT.>KHf CHH.>KaeT TBep,UOCTb CTaJIH, YJIYlJlllaeT

 


o6pa6aTbIBaeMOCTb H/HJUI HJMeJibqaeT JepHO c ycTpaHeHHeM CTpyi<:­ TYPHOH HeO,LJ.Hopo,LJ.HOCTH nYTeM noJIHOH nepeKpHCTaJIJIHJaUHH •.LJ.mp­

cPYJHOHHhIH OTIKHr oco6eHHO Ba)l(eH,ll.JISI nopOlUKOBb X MaTepHaJIOB c reTeporeHHOH HJIH HeO,LJ.HOpO,ll.HOH CTpYKTYPOH, TaK KaK noJBOJISleT

o6ecneqHTb O,ll.HHaKOBbie CBOHCTBa no BCeMy ceqeHHIO HJ,LJ.eJIHSI.

3aKaJIKa yrnepo,ll.HCTOH CTaJIH npHMeHSleTCSI,ll.JISI nOBbillleHHSI TBep­

,ll.OCTH H npoqHOCTH, a JiempoBaHHOH CTaJIH - KpOMe noBblllleHHSI MexaHHqecKHX CBOHCTB eme H,ll.JISI yJiyqllleHHSI cPHJHKO-XHMHqecKHX CBOHCTB: MarHHTHb X, aHTHKOpp03HOHHbIX H T.,ll..

B nopornKOBhIX CTaJISIX nopHCTOCTh oKaJbIBaeT BJIHSIHHe KaK Ha Ja­ KaJIHBaeMOCTh, TaK H Ha TeXHOJIOfHIO JaKaJIKH H ee peJyJihTaTbl. fio cpaBHeHHIO c JIHTbIMH npH JaKaJIKe nopollIKOBb X CTaJieH IlOBb IllaeT­

CSI BepOSITHOCTb o6pa30BaHHSI «MSlfKHX» IlSITeH, pa36poca TBep,LJ.OCTH H

 

 

a

400

 

 

'-> 360

!>
::e:

"' 320

e


 

 

o6eJyrnepO)l(HBaH HSI HJ,LJ.eJIHH. lpHqHHaMH pa36poca TBep,ll.OCTH MO­ fYT 6b Tb HepaBHOMepHOe pacnpe,LJ.eJieHHe yrnepo,LJ.a H nJIOTHOCTH no 06beMy, KOCBeHHOe BJIHSIHHe nop H T.,ll.. fiOSIBJieHHe «MSlfKHX» IlSITeH HanpSIMYIO CBSIJaHO c HaJIHqHeM OTKpb Tb X nop, H3-3a KOTOpblX aK­ THBHaSI noeepXHOCTb HJ,LJ.eJIHSI CTaHOBHTCSI MHOro 60Jibllle ero ra6a­ pHTHOH noeepxHOCTH. TaK KaK OXJia)l(,ll.a10m 11e)l(H,ll.KOCTH, npHMeHsie­ Mb e npH JaKaJIKe (HanpHMep, BO,LJ.a) o6Jia,LJ.aIOT,ll.OCTaToqHo HHJKHMH TeMnepaTYPaMH KHneHHSI H BSIJKOCTSIMH, TO npH norpeHHH B HHX

HarpeTb X TeJI napoo6pa30BaHHe H,LJ.eT He TOJibKO Ha ra6apHTHOH no­ eepXHOCTH, HO H B nopax, r,LJ.e o6pa30BaBIIIHeCSI ycToiiqHBbie nyJb pb­ KH YMeHblllaIOT noeepXHOCTb TenJIOOTBO,LJ.a, CHH)l(aSI 06IUYIO CKOpOCTb OXJia)l(,ll.eHHSI H, COOTBeTCTBeHHO, TBep,ll.OCTb HJ,LJ.eJIHH.

IlpH JaKaJIKe JIHTb X 6ecnopHCTbIX CTaJieH B peJyJihTaTe MapTeH­ CHTHOro npeepameHHSI B HJ,LJ.eJIHSIX BOJHHKaIOT pa3JIHqHb e HanpIDKe­ HHSI: TepM11qecKHe (,LJ.eQ>opMaUHOHHb e), CBSIJaHHb e c HepaBHOMep­ Hb M pacnpe,LJ.eJieHHeM TeMnepaTYphI no o6beMy HJ,LJ.eJIHSI; Q>aJOBh e, CBSIJaHHbie c HeKorepeHTHOCTbIO o6pa30BaBlUHXCSI Q>aJ; cy6MHKpoc­ KOnHqeCKHe, Bb JBaHHbie HCKa)l(eHHSIMH B KpHCTaJIJIHqeCKOH pellleT­ Ke. B nopornKOBh X CTaJISIX K HHM,LJ.06aBJIS1IOTCS1 HanpIDKeHHSI, o6ycJioB­

JieHHh e HaJIHqHeM nop, Me)l(qaCTHqHb X rpaHHU, XHMHqecKOH HeO,LJ.­ HOpO,ll.HOCTbIO aycreHHTa. BcJie,LJ.CTBHe 3Toro npH onpe,LJ.eJieHHOM ypoe­


<::

'I:


280

 

 

240

 

 

200

 

9000


He nopHCTOCTH nocJie JaKaJIKH TBep,ll.OCTb nopOIIIKOBOro MaTepHaJia B03pacrneT, a npoqHoCTb JIH60 He HJMeHSieTCSI, JIH60 HeMHOro CHH­

)l(aeTCSI. B CBSIJH c 3THM Ja,LJ.aqa oTnycKa KaK TepM11qecKoii o6pa6oTKH, CJie,LJ.y10meii Ja JaKaJIKOH nopOlUKOBb X CTaJieH, JaKJIJOqaeTCSI B CHSl­ THH OCTaTOqHbIX HanpIDKeHHH H nOBbIIlleHHH npoqHOCTH, MaKCH­

MaJibHOe JHaqeHHe KOTOpOH,ll.OCTHraeTCSI npH npoBe,LJ.eHHH OTnycKa B

,LJ.HanaJoHe 200-450 ·c.


...
8000

c::

::E: 7000

s4


6

OopOlUKOBbie MaTepHaJibl Ha OCHOBe UBeTHblX MeTaJIJIOB TaK)l(e

MOfYT no,LJ.BepraTbCSI OT)l(Hry, JaKaJIKe H OTilYCKY.

JlaTYHH (B TOM q11cJie H nopOlUKOBbie) CKJIOHHbl K KOpp03HH no,LJ.


,g 6000

5000

4000

3000

0 4


 

 

8 12 16 20 24 28 32

nopucmocmb, %


 

,LJ.eHCTBHeM OCTaTOqHbIX HanpSl)l(eHHH, no3TOMY He peKQMeH,LJ.yeTCSI HCnOJibJOBaTb HeOTO)l()l(eHHbie,LJ.eTaJIH, noJiyqeHHbie XOJIO,ll.HOH,LJ.eQ>op­ MauHeH cneqeHHhIX JaroTOBOK, a TaK)l(e npowe,LJ.wHe o6pa6oTKY peJa­ HHeM (ToqeHHeM, Q>pe3epoBaHHeM, lUJIHcPOBaHHeM, ceepJieHHeM, Ha­

pe3KOH OTBepCTHH). HHJKOTeMnepaTYPHhIH OTIKHr JiaTYHeH npoBO,ll.HTCSI

B HHTepBaJie 400-500 ·c, npH 3TOM pa3Mepbl,LJ.eTaJieH npaKTHqeCKH

He MeHSIIOTCSI H COXpaHSleTCSI BbICOKaSI qffCTOTa noBepXHOCTH. Ilepe,LJ.


P11c. 275. BJJHHHHe nop11crocrn Ha TeMnepaTYPy Ha'mJJa MaplCHCHTHoro npeepameHHH

M" cTanell 45(/), 50H (2), 70H M (3), Y8(4) 11 Yl 2 (5) (a) 11 TBep,UOCTb MapTeHCHTa

nopowKoeoll CTaJJH Y8 np11 HenpepblBHOM oXJJa)((JleHHH (/) 11 HJOTepMH'leCKOM npeepaIUCHHH (//) (6)


MexaHHqecKOH o6pa6oTKOH c 60JiblUOH CTeneHbIO,LJ.eQ>opMaUHH (Ha­

 

npHMep, npH HaHeCeHHH pe3b6bI HaKaTKOH) npOBO,ll.HTCSI OT)l(Hf np11 850 ·c e TeqeHHe 1 q_


l

,LI.mi IIOBb IIIeHH.H <l>H3HKO-XHMHqecKHX H MexaHffqeCKHX CBOHCTB

IIOpOIIIKOBb X a.JIIOMHHHeBb X CIIJiaBOB HX IIO,llBepraIOT JaKarrKe B BO.llY

1
c reMrrepaTYPbI 490-530 ·c c rrocJie,llyIOIUHM crnpeH'.HeM. TaK, rro­ IpoIIIKOBh H MarepHarr B-95 JaKa.JIHBaIOT, rrpe,llBapHTeJibHO Bbl,llepxaB Iero rrpH 470-493 ·c B reqeHHe 2-4 q, H COCTapHBaIOT B,ll,Be CTa,llHH: (rrpH reMrrepaTYpax 107-135 ·c H 163-177 ·c. nocJie 3Toro B-95 rrpH­

o6perneT IIOBb IIIeHHYIO CTOHKOCTb K KOpp03HH.

nocKOJihKY rropHCTb e (oco6eHHO KpyrrHora6apHTHb e) rropoIII­ KOBh e H3,lleJIH.H Ha OCHOBe qepHbIX H UBeTHb X MeTa.JIJIOB 6oJiee qyB­ CTBHTeJibHbl K TepMHqeCKHM Hallp.H)l(eHH.HM, qeM JIHTb e 6ecrropHC­ Tb e, pe)l(HM HarpeBa Bb 6HpaIOT TaK, qTo6bIo6ecrreqHTb MaKCHMa.Jlb­ HO 6b CTpbIH rrporpeB,llO 3a,llaHHOH TeMrrepaTYPbI6e3 B03HHKHOBeHH.H TpeIUHH, Kopo6JieHH.H H T.II. lpH Ha.JIHqHH IIOJIHMOp<i>HhlX rrpeBpame­ HH.H B HarpeBaeMb X MaTepHarrax B6JIH3H TOqeK rrepexo,lla CJie,llyeT JIH6o YMeHbIIIaTb CKOpOCTH HarpeBa, JIH6o,lleJiaTb H30TepMffqeCKYIO Bbl,llep­

XKY· Oco6oe BHHMaHHe cJie,llyeT y,lleJI.HTh HarpeBy HJ,lleJIHH c pe3KHMH

rrepexo,llaMH OT TOJICTblX ceqeHHH K TOHKHM, IIOCKOJibKY TOHKHe rrpo­ rpeBaIOTC.H 6b CTpee, qTo rrpHBO,llHT K TepMHqecKHM Harrp.HXeHH.HM, pacTpeCKHBaHHIO H Kopo6JieHHIO. BbICOKorropHCTbie HJ,lleJIH.H He cJie­

.llYeT HarpeBaTb IIO,ll JaKa.JIKY B COJieBb X pacIIJiaBax H OXJia)l(,llaTb B co­ JieBb X pacTBopax, rroToMy qTo coJIH oqeHb CJIO)l(HO Y.lla.JI.HTh HJ rrop, a H3,lleJIH.H rrpH 3TOM IIO,llBepraIOTC.H 3JieKTpOXHMHqeCKOH KOpp03HH.

•HarpeB rropOIIIKOBb X MaTepHa.JIOB rrpH TepMHqecKOH o6pa60TKe Heo6XO,llHMO rrpOBO,llHTb B rreqax c JaIUHTHOH cpe,llOH, TaK KaK rro­ pOIIIKOBb e H3,lleJIH.H o6Jia,llaIOT 60JibllIOH aKTHBHOH IIOBepXHOCTbIO (HCKJIJOqeHHe COCTaBJISleT JaKa.JIKa TOKaMH Bb COKOH qacTOTbl). B Kaqe­ CTBe TaKHX cpe,ll HCIIOJib3YJOT aJOT c He60JibllIHMH rrpHMeCSIMH BO,llO­ po,lla H CO, BO.llOPO.ll, 3H,ll,Ora3, KOHBepTHpoBaHHbIH npHpO,llHh H raJ, BO,llopo,ll c.llo6aBKaMH IIPHPO.llHOro raJa. B cJiyqae OTCYTCTBHSI neqHoro o6opy,llOBaHHSI, pacctiHTaHHOfO Ha pa60TY c yKa3aHHbl MH aTMoc<t>e­ paMH, MO)l(HO BOCIIOJlb30BaTbCSI KOHTeHHepaMH c yrnepO,llCO,llepxa­ IUHMH JaCbIIIKaMH (,llpeBeCHbIM yrneM, rpa<t>HTOM, caxeH: HJIH HX CMe­ CSIMH).,lJ.JIHTeJibHOCTb H30TepMHqecKOH Bb,llep)l(KH rrpH HarpeBe JaBH­ CHT OT pa3MepoB H3,lleJIHSI H OT CKOpOCTH COOTBeTCTBYIOIU HX rrpeepa­

IUeHHH, COBepIIIaIOIUHXCSI B HarpeBaeMOM MaTepHarre; OHO He,llOJI)l(HO 6b Tb 60JibIIIe Toro BpeMeHH, KOTOpoe Tpe6yeTCSI,llJI.H JaBeprneHHSI IlpOHCXO,llSIIUHX B rropOIIIKOBOM MaTepHaJie CTpYKTYPHbIX npeBpame­ HHH.


 



Поделиться:


Последнее изменение этой страницы: 2016-04-23; просмотров: 289; Нарушение авторского права страницы; Мы поможем в написании вашей работы!

infopedia.su Все материалы представленные на сайте исключительно с целью ознакомления читателями и не преследуют коммерческих целей или нарушение авторских прав. Обратная связь - 18.218.61.16 (0.038 с.)