Tshav kub-resistant alloys. Tshwj xeeb steels thiab alloys. Kev tsim khoom thiab siv cov khoom siv hluav taws xob kub-resistant

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

Kev lag luam niaj hnub tsis tuaj yeem xav txog yam tsis muaj cov khoom siv hlau. Peb ntsib nws ntawm yuav luag txhua qhov tig. Los ntawm kev qhia ntau yam tshuaj rau hauv nws cov muaj pes tsawg leeg, cov khoom siv kho tshuab thiab kev ua haujlwm tuaj yeem txhim kho tau zoo.

Dab tsi yog steel

Hlau yog cov hlau uas muaj cov pa roj carbon thiab hlau. Tsis tas li ntawd, xws li cov hlau (daim duab hauv qab no) tej zaum yuav muaj impurities ntawm lwm yam tshuaj.

Muaj ntau lub xeev cov qauv. Yog tias cov ntsiab lus carbon nyob rau hauv thaj tsam ntawm 0.025-0.8%, ces cov hlau no hu ua hypoeutecoid thiab muaj pearlite thiab ferrite hauv lawv cov qauv. Yog hais tias cov hlau yog hypereutectoid, ces cov theem pearlitic thiab cementite tuaj yeem pom. Ib qho tshwj xeeb ntawm cov qauv ferrite yog nws cov yas siab. Cementite kuj tseem muaj qhov nyuaj heev. Perlite tsim ob theem dhau los. Nws tuaj yeem muaj cov duab granular (suav nrog cementite nyob rau hauv cov nplej ntawm ferrite, uas muaj ib puag ncig zoo) thiab lamellar (ob theem zoo li daim hlau). Yog hais tias steel yog rhuab tshaj qhov kub ntawm qhov uasKev hloov kho polymorphic tshwm sim, cov qauv hloov mus rau austenitic. Cov theem no tau nce plasticity. Yog tias cov ntsiab lus carbon ntau tshaj 2.14%, ces cov ntaub ntawv thiab cov alloys hu ua cam khwb cia hlau.

Tim steel

Nyob ntawm qhov muaj pes tsawg leeg, hlau tuaj yeem ua carbon thiab alloyed. Cov ntsiab lus carbon tsawg dua 0.25% characterizes me me hlau. Yog tias nws cov nyiaj nce mus txog 0.55%, ces peb tuaj yeem tham txog qhov nruab nrab-carbon alloy. Hlau, uas muaj ntau tshaj 0.6% carbon nyob rau hauv nws muaj pes tsawg leeg, yog hu ua high-carbon steel. Yog hais tias, nyob rau hauv tus txheej txheem ntawm kev tsim ib tug alloy, cov cuab yeej siv rau cov kev taw qhia ntawm cov tshuaj cov ntsiab lus, ces cov hlau no hu ua alloyed. Kev taw qhia ntawm ntau yam khoom tseem ceeb hloov nws cov khoom. Yog tias lawv tus lej tsis tshaj 4%, ces cov hlau tsis tshua muaj alloyed. Nruab nrab-alloyed thiab high-alloyed steel muaj txog li 11% thiab ntau tshaj 12% ntawm kev koom ua ke, feem. Nyob ntawm thaj chaw uas siv cov hlau alloys, muaj ntau yam ntawm lawv: cov cuab yeej, cov qauv thiab tshwj xeeb steels thiab alloys.

Tsev tsim khoom

txheej txheem ntawm smelting steel yog heev laborious. Nws suav nrog ntau theem. Ua ntej tshaj plaws, koj xav tau cov khoom siv raw - hlau ore. Thawj theem suav nrog cua sov mus rau qhov kub thiab txias. Hauv qhov no, cov txheej txheem oxidative tshwm sim. Nyob rau theem ob, qhov kub thiab txias ua ntau dua. Cov txheej txheem ntawm carbon oxidation yog ntau intensive. Ntxiv kev nplua nuj ntawm cov hlau nrog oxygen yog ua tau. Tsis tsim nyog impurities raug tshem tawm hauvslag. Cov kauj ruam tom ntej yog tshem tawm cov pa oxygen ntawm cov hlau, vim nws txo qis cov khoom siv kho tshuab. Qhov no tuaj yeem ua tiav hauv qhov diffusion lossis precipitating yam. Yog tias cov txheej txheem deoxidation tsis tshwm sim, ces cov hlau ua tau raug hu ua boiling steel. Calm alloy tsis emission gases, oxygen raug tshem tawm tag nrho. Ib txoj hauj lwm nruab nrab yog nyob los ntawm ib nrab ntsiag to steels. Kev tsim cov hlau alloys tshwm sim hauv qhov qhib-hearth, induction furnaces, oxygen converters.

Hlau alloying

Yuav kom tau txais qee yam khoom ntawm cov hlau, cov khoom siv tshwj xeeb alloying tau nkag rau hauv nws cov muaj pes tsawg leeg. Lub ntsiab zoo ntawm cov hlau no yog ua kom muaj zog tiv thaiv ntau yam deformations, kev ntseeg siab ntawm cov khoom thiab lwm yam khoom tsim tau nce ntau. Hardening txo qhov feem pua ntawm cov kab nrib pleb thiab lwm yam tsis xws luag. Feem ntau cov qauv no ntawm saturation nrog cov ntsiab lus sib txawv yog siv los cuam tshuam rau cov tshuaj corrosion. Tab sis kuj muaj ntau qhov tsis zoo. Lawv yuav tsum tau ua ntxiv, qhov tshwm sim ntawm cov tsos ntawm flakes yog siab. Tsis tas li ntawd, tus nqi ntawm cov khoom kuj nce. Cov ntsiab lus alloying feem ntau yog chromium, npib tsib xee, tungsten, molybdenum, cob alt. Scope ntawm lawv daim ntawv thov yog heev loj. Qhov no suav nrog kev tsim kho tshuab, thiab tsim cov khoom siv rau cov kav dej, cov chaw tsim hluav taws xob, aviation thiab ntau ntxiv.

Lub tswv yim ntawm kev ua kom sov thiab kub ua haujlwm

Lub tswv yim ntawm kev ua kom sov yog hais txog lub peev xwm ntawm cov hlau lossis hlau kom khaws tag nrho nws cov yam ntxwv thaum ua haujlwm ntawm qhov kub thiab txias. Nyob rau hauv ib puag ncig zoo li no, feem ntaugas corrosion yog pom. Yog li ntawd, cov khoom yuav tsum tau resistant rau nws cov kev ua, uas yog, yuav tsum tau tshav kub-resistant. Yog li, tus cwj pwm ntawm cov alloys uas siv rau ntawm qhov kub thiab txias yuav tsum suav nrog ob lub ntsiab lus no. Tsuas yog tom qab ntawd cov hlau no yuav muab lub neej tsim nyog rau cov khoom, cov cuab yeej thiab lwm yam khoom siv.

Txheej Txheem Ntawm Cov Hlau Kub Kub

Nyob rau hauv rooj plaub uas qhov kub nce mus txog qhov tseem ceeb, yuav tsum tau siv cov alloys uas yuav tsis tawg thiab succumb rau deformation. Nyob rau hauv cov ntaub ntawv no, tshav kub-resistant alloys yog siv. Kev khiav hauj lwm kub rau cov ntaub ntawv no yog siab tshaj 500ºС. Cov ntsiab lus tseem ceeb uas qhia txog cov hlau zoo li no yog qhov muaj kev tiv thaiv siab, plasticity, uas nyob rau lub sijhawm ntev, nrog rau kev so kom txaus. Muaj ntau lub ntsiab lus uas tuaj yeem ua rau muaj kev kub ntxhov ntau ntxiv: cob alt, tungsten, molybdenum. Chromium kuj tseem yog ib qho yuav tsum tau ua. Nws tsis cuam tshuam rau lub zog ntau npaum li nws ua rau qhov ntsuas tsis kam. Chromium kuj tiv thaiv cov txheej txheem corrosion. Lwm tus yam ntxwv tseem ceeb ntawm alloys ntawm hom no yog qeeb creep.

Kev faib tawm ntawm cov cua sov-resistant steels los ntawm cov qauv

Kub-tiv taus thiab kub-resistant alloys yog cov chav kawm ferritic, martensitic, austenitic thiab nrog cov qauv ferritic-martensitic. Cov qub muaj li ntawm 30% chromium. Tom qab kev ua haujlwm tshwj xeeb, cov qauv ua zoo-grained. Yog hais tias cov cua kub kub tshaj 850ºC, ces cov nplejnce, thiab xws li cov ntaub ntawv kub-resistant ua nkig. Cov chav kawm martensitic yog tus cwj pwm los ntawm cov ntsiab lus chromium hauv qab no: los ntawm 4% mus rau 12%. Nickel, tungsten thiab lwm yam ntsiab lus kuj tseem muaj nyob rau hauv me me. Qhov chaw ntawm turbines thiab li qub hauv tsheb yog tsim los ntawm lawv. Cov hlau uas muaj martensite thiab ferrite hauv lawv cov qauv tsim nyog rau kev ua haujlwm ntawm qhov kub thiab txias thiab ua haujlwm ntev. Cov ntsiab lus chromium nce mus txog 14%. Austenite tau txais los ntawm kev qhia nickel rau hauv cov khoom siv hluav taws kub-resistant. Cov hlau uas muaj cov qauv zoo sib xws muaj ntau qib.

Nickel raws alloys

Nickel muaj ntau yam khoom muaj txiaj ntsig. Nws muaj txiaj ntsig zoo rau kev ua haujlwm ntawm cov hlau (ob leeg kub thiab txias). Yog hais tias ib feem los yog cov cuab yeej tsim los ua hauj lwm nyob rau hauv ib qho kev txhoj puab heev ib puag ncig, ces alloying nrog cov khoom no ho nce corrosion kuj. Nickel-based heat-resistant cov ntaub ntawv tau muab faib ua pawg hauv qab no: kub-tiv taus thiab ua tau kub-resistant. Cov yav tas yuav tsum muaj yam tsawg kawg nkaus kub-resistant yam ntxwv. Ua haujlwm kub ncav cuag 1200ºC. Tsis tas li ntawd, chromium los yog titanium ntxiv. Yam ntxwv, steels alloyed nrog npib tsib xee muaj ib tug me me ntawm impurities xws li barium, magnesium, boron, yog li ntawd lub grain ciam teb yuav ntxiv dag zog rau. Thaum tshav kub kub-resistant alloys ntawm hom no yog tsim nyob rau hauv daim ntawv ntawm forgings thiab dov khoom. Nws kuj tseem ua tau los nrum qhov chaw. Lawv lub ntsiab ntawm daim ntawv thov yog kev tsim cov roj turbine ntsiab. Nickel-based heat-resistant alloys muaj txog li 30% chromium. Lawv qiv lawv tus kheej zoo txaus rau stamping, vuam. Tsis tas li ntawd, qhov ntsuas tsis kam yog nyob rau theem siab. Qhov no ua rau nws muaj peev xwm siv tau rau hauv cov raj xa dej.

Kub-resistant titanium alloy steel

Titanium tau qhia hauv me me (txog 0.3%). Nyob rau hauv cov ntaub ntawv no, nws nce lub zog ntawm lub alloy. Yog hais tias nws cov ntsiab lus yog ntau dua, ces qee yam khoom deteriorate (hardness, zog). Tab sis lub plasticity nce. Qhov no txhawb kev ua cov hlau. Nrog rau kev taw qhia ntawm titanium ua ke nrog lwm cov khoom, nws muaj peev xwm ua tau kom zoo dua cov yam ntxwv kub-resistant. Yog tias muaj kev xav tau los ua haujlwm hauv qhov chaw nruj heev (tshwj xeeb tshaj yog thaum tus qauv tsim muaj kev sib txuas), ces alloying nrog cov tshuaj no yog tsim nyog.

Cob alt alloys

Ntau cov cob alt ntau (txog 80%) mus rau cov khoom siv xws li cov khoom siv hluav taws xob thiab cov khoom siv hluav taws xob, vim nws tsis tshua muaj siv hauv nws daim ntawv ntshiab. Nws qhov kev taw qhia nce plasticity, nrog rau kev tiv thaiv thaum ua haujlwm ntawm qhov kub thiab txias. Thiab qhov siab dua, qhov ntau dua ntawm cob alt nkag rau hauv cov hlau. Hauv qee hom, nws cov ntsiab lus nce mus txog 30%. Lwm cov yam ntxwv ntawm cov hlau zoo li no yog kev txhim kho hauv cov khoom sib nqus. Txawm li cas los xij, vim yog tus nqi siab ntawm cob alt, nws siv yog qhov txwv.

Kev cuam tshuam ntawm molybdenum ntawm cov khoom kub-tiv taus

Cov tshuaj no cuam tshuam rau lub zog ntawm cov khoom ntawm qhov kub thiab txias.

Nws yog qhov tshwj xeeb tshaj yog thaum siv ua ke nrog lwm cov ntsiab lus. Nws nce hardness ntawm steel (twb ntawm cov ntsiab lus ntawm 0.3%). Lub zog tensile kuj nce. Lwm qhov zoo tshaj plaws uas kub-resistant alloys alloyed nrog molybdenum muaj yog qhov siab ntawm kev tiv thaiv oxidative txheej txheem. Molybdenum pab txhawb kev sib tsoo ntawm cov nplej. Qhov tsis zoo yog qhov nyuaj ntawm vuam.

Lwm yam tshwj xeeb steels thiab alloys

Yuav ua tau tej yam dej num, yuav tsum tau cov ntaub ntawv uas muaj tej yam khoom. Yog li, peb tuaj yeem tham txog kev siv cov alloys tshwj xeeb, uas tuaj yeem ua tau ob qho tib si alloyed thiab carbon. Nyob rau hauv lub tom kawg, cov txheej txheem ntawm cov yam ntxwv yuav tsum tau ua tiav vim qhov tseeb tias kev tsim cov alloys thiab lawv cov txheej txheem yuav siv qhov chaw siv cov cuab yeej tshwj xeeb. Txawm tias tshwj xeeb alloys thiab steels tau muab faib ua cov qauv thiab cov cuab yeej. Ntawm cov haujlwm tseem ceeb ntawm cov khoom siv no, cov hauv qab no tuaj yeem paub qhov txawv: kev tiv thaiv corrosion thiab hnav cov txheej txheem, kev muaj peev xwm ua haujlwm hauv ib puag ncig hnyav, thiab txhim kho cov yam ntxwv ntawm kev siv tshuab. Cov pawg no suav nrog cov hlau tsis muaj cua sov thiab cov hlau alloys uas muaj kev ua haujlwm siab, thiab cov hlau cryogenic uas tuaj yeem tiv taus txog -296ºС.

Tshooj steel

Tshwj xeeb cov cuab yeej steel yog siv los tsim cov cuab yeej. Vim tias lawv cov kev ua haujlwm sib txawv, cov khoom siv kuj raug xaiv ib tus zuj zus. Txij li cov kev xav tau rau cov cuab yeej muaj siab heev, cov yam ntxwv ntawm cov alloys rau lawvntau lawm yog qhov tsim nyog: lawv yuav tsum tsis pub dawb ntawm cov neeg thib peb impurities, suav nrog, cov txheej txheem deoxidation yog ua tau zoo, thiab cov qauv yog homogeneous. Nws yog ib qho tseem ceeb heev rau kev ntsuas ntsuas kom muaj qhov ruaj khov thiab tiv taus hnav. Yog tias peb tham txog cov cuab yeej txiav, ces lawv ua haujlwm ntawm qhov kub siab (muaj cua sov ntawm ntug), kev sib txhuam tsis tu ncua thiab deformation. Yog li ntawd, nws yog ib qho tseem ceeb heev rau lawv kom lawv cov thawj hardness thaum rhuab. Lwm hom cuab yeej steel yog kev kub ceev steel. Yeej, nws yog doped nrog tungsten. Hardness yog khaws cia txog li 600ºС. Kuj tseem muaj cov hlau tuag. Lawv yog tsim los rau ob qho tib si kub thiab txias sib sau.

Tshwj xeeb Alloy Applications

Kev lag luam uas siv cov alloys nrog cov yam ntxwv tshwj xeeb muaj ntau yam. Vim lawv cov kev txhim kho zoo, lawv yog qhov tseem ceeb hauv kev tsim kho tshuab, kev tsim kho, thiab kev lag luam roj. Thaum tshav kub kub-resistant thiab kub-resistant alloys yog siv nyob rau hauv kev tsim cov turbine qhov chaw, spare qhov chaw rau tsheb. Cov hlau uas muaj cov yam ntxwv zoo tiv thaiv corrosion yog qhov tseem ceeb rau kev tsim cov kav dej, cov koob carburetor, disks, thiab ntau yam khoom ntawm kev lag luam tshuaj. Railway rails, thoob, lem rau tsheb - hnav-resistant steels yog lub hauv paus rau tag nrho cov no. Hauv kev tsim cov bolts, txiv ntseej thiab lwm yam zoo sib xws, cov hlau tsis siv neeg siv tau. Cov springs yuav tsum txaus elastic thiab hnav-resistant. Yog vim li cascov khoom siv rau lawv yog caij nplooj ntoos hlav steel. Txhawm rau txhim kho qhov zoo no, lawv tau ntxiv alloyed nrog chromium, molybdenum. Txhua qhov tshwj xeeb alloys thiab steels nrog cov txheej txheem tshwj xeeb tuaj yeem txo tus nqi ntawm qhov chaw uas tsis yog hlau siv yav dhau los.