Kev kho cua sov ntawm cov hlau. Hom kev kho cua sov

2024 Tus sau: Howard Calhoun | [email protected]. Kawg hloov kho: 2023-12-17 10:28

Kev kho cua sov ntawm cov hlau yog qhov tseem ceeb ntawm cov txheej txheem tsim khoom ntawm ferrous thiab non-ferrous metallurgy. Raws li cov txheej txheem no, cov hlau muaj peev xwm hloov tau lawv cov yam ntxwv rau qhov yuav tsum tau muaj. Hauv kab lus no, peb yuav txiav txim siab txog hom kev kho cua sov siv hauv kev lag luam niaj hnub no.

Qhov tseem ceeb ntawm kev kho cua sov

Thaum lub sijhawm tsim cov khoom lag luam ib nrab tiav, cov khoom siv hlau raug kho kom sov kom lawv cov khoom xav tau (lub zog, tiv thaiv corrosion thiab hnav, thiab lwm yam). Kev kho cua sov ntawm cov hlau yog ib txheej ntawm cov txheej txheem tsim cov txheej txheem thaum lub sij hawm cov txheej txheem thiab lub cev thiab kev hloov pauv ntawm cov hlau nyob rau hauv lub siab kub, tab sis cov tshuaj muaj pes tsawg leeg ntawm cov khoom yog khaws cia.

hom phiaj kho cua sov

Cov khoom siv hlau uas siv txhua hnub hauv txhua qhov kev lag luam hauv lub tebchaws yuav tsum ua kom tau raws li qhov xav tau siab rau kev hnav tsis kam. Hlau, raws li cov khoom siv raw, yuav tsum tau ntxiv dag zog rau cov khoom tsim nyog, uas tuaj yeem ua tauraug rau qhov kub thiab txias. Thaum tshav kub kub kev kho mob ntawm alloys nrog kub kub hloov lub thawj qauv ntawm ib yam khoom, redistributes nws constituent Cheebtsam, transforms loj thiab cov duab ntawm crystals. Tag nrho cov no ua rau txo qis ntawm cov kev ntxhov siab sab hauv ntawm cov hlau thiab yog li ua rau nws lub cev thiab cov khoom siv kho tshuab.

Kev kho cua sov

Kev kho cua sov ntawm cov hlau alloys los ntawm peb txoj haujlwm yooj yim: cua sov cov khoom siv (cov khoom ib nrab tiav) mus rau qhov xav tau kub, ua kom nws nyob rau hauv cov xwm txheej tshwj xeeb rau lub sijhawm xav tau thiab txias sai. Hauv kev tsim khoom niaj hnub no, siv ntau hom kev kho cua sov, uas txawv ntawm qee qhov kev siv tshuab, tab sis cov txheej txheem algorithm feem ntau tseem zoo ib yam nyob txhua qhov chaw.

Raws li cov txheej txheem ntawm kev kho cua sov, muaj cov hauv qab no:

• Thermal (hardening, tempering, annealing, aging, cryogenic kho).
• Kev kho cua sov-tshuab muaj kev kho kub kub ua ke nrog kev ua haujlwm ntawm cov hlau.
• Chemico-thermal koom nrog kev kho cua sov ntawm cov hlau, ua raws li kev txhim kho ntawm cov khoom nto nrog cov tshuaj (carbon, nitrogen, chromium, thiab lwm yam).

Annealing yog txheej txheem tsim khoom uas cov hlau thiab cov hlau yog rhuab mus rau qhov kub thiab txias, thiab tom qab ntawd, ua ke nrog rau lub cub tawg uas cov txheej txheem coj qhov chaw, txias heev maj mam. Raws li qhov tshwm sim ntawm annealing, nws muaj peev xwm tshem tawm cov inhomogeneities ntawm cov tshuaj muaj pes tsawg leegtshuaj, txo cov kev ntxhov siab sab hauv, ua tiav cov qauv granular thiab txhim kho nws li, nrog rau txo cov hardness ntawm alloy los pab txhawb nws txoj kev ua haujlwm ntxiv. Muaj ob hom annealing: annealing ntawm thawj thiab thib ob hom.

Thawj-chav annealing txhais tau hais tias kev kho cua sov, vim qhov kev hloov pauv me me lossis tsis muaj qhov hloov pauv hauv lub xeev ntawm cov hlau. Nws kuj muaj nws tus kheej ntau yam: homogenized - annealing kub yog 1100-1200, nyob rau hauv xws li mob cov alloys yog khaws cia rau 8-15 teev, recrystallization (ntawm t 100-200) annealing yog siv rau riveted steel, uas yog, deformed lawm. ua txias.

Annealing ntawm hom thib ob ua rau muaj kev hloov pauv tseem ceeb hauv cov hlau. Nws kuj muaj ntau yam:

• Tag nrho annealing - cua sov lub alloy 30-50 saum toj no qhov tseem ceeb kub cim cim ntawm cov khoom no thiab txias ntawm tus nqi teev (200 / teev - carbon steels, 100 / teev thiab 50 / teev - low-alloy thiab siab -alloy steels, ntsig txog).
• Tsis tiav - cua sov rau qhov tseem ceeb thiab txias qeeb.
• Diffusion - annealing kub 1100-1200.
• Isothermal - cua sov tshwm sim tib yam li nrog rau tag nrho cov annealing, txawm li cas los xij, tom qab ntawd, kev txias sai yog nqa mus rau qhov kub thiab txias me ntsis hauv qab qhov tseem ceeb thiab sab laug kom txias hauv huab cua.
• Normalized - ua tiav annealing nrog tom qab txias ntawm cov hlau hauv huab cua, thiab tsis nyob hauv lub cub tawg.

Nyob zoo ib tsoom phooj ywg sawv daws

Tempering is manipulationnrog ib tug alloy, lub hom phiaj ntawm uas yog ua kom tiav ib tug martensitic transformation ntawm cov hlau, uas txo cov ductility ntawm cov khoom thiab ua rau kom nws lub zog. quenching, nrog rau annealing, muaj cua sov cov hlau nyob rau hauv lub cub tawg saum toj no qhov tseem ceeb kub rau lub quenching kub, qhov sib txawv nyob rau hauv lub siab txias npaum li cas tshwm sim nyob rau hauv cov kua da dej. Nyob ntawm cov hlau thiab txawm tias nws cov duab, ntau hom hardening yog siv:

• Kev sib zog rau tib qhov chaw, uas yog, hauv tib da dej nrog kua (dej rau qhov loj, roj rau qhov me me).
• Kev sib zog ua kom tawv nqaij - qhov txias yuav tshwm sim hauv ob theem ua tiav: thawj zaug hauv cov kua (ib lub tshuab ua kom txias) mus rau qhov kub ntawm kwv yees li 300, tom qab ntawd hauv huab cua lossis hauv lwm chav roj.
• Stepped - thaum cov khoom nce mus txog qhov kub thiab txias, nws tau txias rau qee lub sijhawm hauv cov ntsev ntsev, tom qab ntawd txias hauv huab cua.
• Isothermal - thev naus laus zis zoo ib yam li cov kauj ruam hardening, txawv tsuas yog lub sijhawm tuav ntawm cov khoom ntawm martensitic transformation kub.
• Tus kheej-tempering hardening txawv ntawm lwm hom nyob rau hauv uas cov rhuab hlau tsis yog kiag li txias, tawm hauv ib tug sov so cheeb tsam nyob rau hauv nruab nrab ntawm ib feem. Raws li qhov tshwm sim ntawm qhov kev tswj hwm no, cov khoom lag luam tau txais cov khoom muaj zog ntxiv ntawm qhov chaw thiab siab viscosity hauv nruab nrab. Qhov kev sib xyaw ua ke no yog qhov tseem ceeb rau cov twj paj nruag (hammers, chisels, thiab lwm yam)

Vajtswv

Tempering yog theem kawg ntawm kev kho cua sov ntawm cov hlau, uas txiav txim siabcov qauv kawg ntawm cov hlau. Lub hom phiaj tseem ceeb ntawm tempering yog txo cov brittleness ntawm cov khoom hlau. Lub hauv paus ntsiab lus yog kom sov ib feem mus rau qhov kub ntawm qhov kub thiab txias thiab txias. Txij li cov hom kev kho cua sov thiab cov cua txias ntawm cov khoom hlau rau ntau lub hom phiaj yuav txawv, muaj peb hom tempering:

• High - qhov cua sov yog los ntawm 350-600 rau tus nqi qis dua qhov tseem ceeb. Cov txheej txheem no feem ntau yog siv rau cov qauv hlau.
• Nruab nrab - kev kho cua sov ntawm t 350-500, feem ntau rau cov khoom caij nplooj ntoos hlav thiab caij nplooj ntoos hlav.
• Tsawg - qhov cua kub ntawm cov khoom tsis siab tshaj 250, uas tso cai rau kom ua tiav lub zog siab thiab hnav tsis kam ntawm qhov chaw.

Nyiaj

Kev laus yog kev kho cua sov ntawm cov hlau, ua rau cov txheej txheem ntawm decomposition ntawm cov hlau supersaturated tom qab quenching. Qhov tshwm sim ntawm kev laus yog qhov nce hauv qhov txwv ntawm hardness, tawm los thiab lub zog ntawm cov khoom tiav. Tsis tsuas yog cam khwb cia hlau yog raug rau kev laus, tab sis kuj tsis yog-ferrous hlau, xws li yooj yim deformable aluminium alloys. Yog hais tias cov khoom hlau raug rau hardening yog khaws cia nyob rau hauv ib txwm kub, cov txheej txheem tshwm sim nyob rau hauv nws uas ua rau ib tug spontaneous nce nyob rau hauv lub zog thiab ib tug txo nyob rau hauv ductility. Qhov no yog hu ua kev laus ntawm cov hlau. Yog hais tias tib yam manipulation ua tiav ntawm qhov kub siab, nws yuav hu ua kev laus laus.

Cryogenic kho

Hloov pauv hauv cov qauv ntawm cov hlau,uas txhais tau hais tias lawv cov khoom tuaj yeem ua tiav tsis yog los ntawm qhov siab, tab sis kuj los ntawm qhov kub tsis tshua muaj siab. Kev kho cua sov ntawm cov alloys ntawm t hauv qab xoom yog hu ua cryogenic. Cov thev naus laus zis no tau siv dav hauv ntau qhov haujlwm ntawm kev lag luam hauv tebchaws raws li kev ntxiv rau kev kho cua sov, vim nws tuaj yeem txo tus nqi ntawm cov txheej txheem thermal hardening.

Cryogenic kev kho mob ntawm cov hlau yog nqa tawm ntawm t -196 hauv cov txheej txheem tshwj xeeb cryogenic. Cov thev naus laus zis no tuaj yeem ua rau lub neej ua haujlwm tau zoo ntawm cov tshuab ua haujlwm thiab cov khoom tiv thaiv corrosion, thiab tshem tawm qhov xav tau kev kho dua tshiab.

Thermo-mechanical kev kho mob

Ib txoj kev tshiab ntawm kev ua cov alloys ua ke ua cov hlau ntawm qhov kub thiab txias nrog cov khoom siv deformation ntawm cov khoom uas nyob rau hauv lub xeev yas. Thermomechanical kho (TMT) raws li txoj kev ua tiav tuaj yeem yog peb hom:

• Tsuas kub TMT muaj ob theem: yas deformation tom qab quenching thiab tempering ntawm ib feem. Qhov sib txawv tseem ceeb ntawm lwm hom TMT yog cov cua kub kub rau lub xeev austenitic ntawm cov hlau.
• Kub-kub TMT suav nrog cua sov cov hlau rau lub xeev martensitic ua ke nrog cov yas deformation.
• Preliminary - deformation yog ua ntawm t 20, ua raws li hardening thiab tempering ntawm cov hlau.

Tshuaj-kwv yees

Hloov cov qauv thiab cov khoom ntawm cov hlaunws kuj tseem ua tau nrog kev pab ntawm cov tshuaj-thermal kev kho mob, uas ua ke nrog thermal thiab tshuaj lom neeg los ntawm cov hlau. Lub hom phiaj tseem ceeb ntawm cov txheej txheem no, ntxiv rau kev ntxiv dag zog rau lub zog, hardness, thiab hnav tsis kam rau cov khoom, kuj tseem yuav muab cov kua qaub tiv thaiv thiab hluav taws tsis kam mus rau ib feem. Cov pab pawg no suav nrog cov kev kho cua sov hauv qab no:

• Cementation yog nqa tawm los muab lub zog ntawm cov khoom ntxiv. Lub ntsiab ntawm txoj kev yog kom saturate cov hlau nrog carbon. Carburizing yuav ua tau nyob rau hauv ob txoj kev: khoom thiab roj carburizing. Hauv thawj kis, cov khoom siv ua tiav, ua ke nrog cov thee thiab nws cov activator, tau muab tso rau hauv lub qhov cub thiab ua kom sov rau qee qhov kub thiab txias, ua raws li tuav hauv qhov chaw no thiab txias. Nyob rau hauv cov ntaub ntawv ntawm cov roj carburizing, cov khoom yog rhuab nyob rau hauv ib lub qhov cub mus txog 900 nyob rau hauv ib tug nruam kwj ntawm carbonaceous gas.
• Nitriding yog tshuaj-kub kho cov khoom hlau los ntawm saturating lawv nto nyob rau hauv ib puag ncig nitrogen. Qhov tshwm sim ntawm cov txheej txheem no yog qhov nce ntawm lub zog tensile ntawm ib feem thiab nce hauv nws cov corrosion kuj.
• Cyanidation yog qhov saturation ntawm cov hlau nrog nitrogen thiab carbon tib lub sijhawm. Qhov nruab nrab tuaj yeem ua kua (molten carbon- thiab nitrogen-muaj ntsev) thiab gaseous.
• Diffusion plating yog ib txoj hauv kev niaj hnub ntawm kev faib cov cua sov, tiv thaiv acid thiab hnav tsis kam rau cov khoom hlau. Qhov saum npoo ntawm cov alloys yog saturated nrog ntau yam hlau (aluminium, chromium) thiab metalloids (silicon, boron).

Txoj KevKev kho cua sov ntawm cam khwb cia hlau

cam khwb cia hlau alloys raug kev kho cua sov siv cov cuab yeej sib txawv me ntsis dua li cov hlau tsis muaj hlau. cam khwb cia hlau (grey, siab-lub zog, alloyed) ua raws li nram no cov kev kho cua sov: annealing (t 500-650), normalization, hardening (nruam, isothermal, nto), tempering, nitriding (grey cam khwb cia hlau), aluminizing (pearlitic cam khwb cia hlau), chromium plating. Tag nrho cov txheej txheem no ua rau muaj txiaj ntsig zoo txhim kho cov khoom ntawm cov khoom siv hlau zaum kawg: ua kom lub neej kev pab cuam, tshem tawm qhov tshwm sim ntawm cov kab nrib pleb thaum siv cov khoom, ua kom lub zog thiab kub tsis kam ntawm cam khwb cia hlau.

Kev kho cua sov ntawm cov hlau tsis muaj hlau

Non-ferrous hlau thiab alloys muaj cov khoom sib txawv ntawm ib leeg, yog li lawv tau ua tiav los ntawm ntau txoj kev. Yog li, tooj liab alloys raug rau recrystallization annealing kom sib npaug cov tshuaj muaj pes tsawg leeg. Rau tooj dag, tsis tshua muaj kub annealing tshuab (200-300) yog muab, vim tias cov hlau no feem ntau ua rau tawg hauv qhov chaw ntub dej. Bronze yog raug rau homogenization thiab annealing ntawm t mus txog 550. Magnesium yog annealed, quenched thiab raug rau kev laus laus (natural aging tsis tshwm sim rau quenched magnesium). Aluminium, zoo li magnesium, dhau los ntawm peb txoj kev kho cua sov: annealing, hardening thiab aging, tom qab uas wrought aluminium alloys ho nce lawv lub zog. Kev ua cov titanium alloys suav nrog: recrystallization annealing, hardening, laus, nitriding thiab carburizing.

CV

Kev kho cua sov ntawm cov hlau thiab alloys yog cov txheej txheem thev naus laus zis hauv ob qho tib si ferrous thiab non-ferrous metallurgy. Cov thev naus laus zis niaj hnub no muaj ntau txoj hauv kev kho cua sov kom ua tiav cov khoom xav tau ntawm txhua hom kev ua tiav. Txhua cov hlau muaj nws tus kheej qhov kub thiab txias, uas txhais tau hais tias kev kho cua sov yuav tsum tau nqa mus rau hauv tus account tus yam ntxwv thiab physico-chemical yam ntxwv ntawm cov khoom. Thaum kawg, qhov no yuav tsis tsuas yog ua tiav cov txiaj ntsig xav tau, tab sis kuj tseem ua kom cov txheej txheem ntau lawm.