Cov Nyhuv ntawm Cov Khoom Sib Xyaws rau Cov Khoom Siv Kho Tshuab ntawm Cov Hlau
Cov hlau ntshiab tsis tshua siv ncaj qha rau hauv cov ntawv thov engineering uas xav tau lub zog siab, tiv taus kev hnav, lossis kev tawv nyob rau hauv cov xwm txheej hnyav. Piv txwv li, txhuas ntshiab yog lub teeb thiab tiv taus corrosion, tab sis mos. Hlau ntshiab yog malleable, tab sis nws lub zog yog txwv. Yog li ntawd, kev lag luam yuav luag ib txwm siv cov hlau alloys, uas yog cov hlau hauv paus sib xyaw nrog lwm cov ntsiab lus hauv cov feem tshwj xeeb kom ua tiav kev sib xyaw ua ke zoo dua ntawm cov khoom. Cov ntsiab lus ntxiv no hu ua alloying elements, thiab lawv cov kev cuam tshuam rau cov khoom siv kho tshuab - xws li lub zog tensile, hardness, ductility, toughness, nkees tsis kam, thiab hnav tsis kam - yog qhov tseem ceeb.
Lub tswv yim yooj yim: vim li cas cov khoom sib xyaw ua ke hloov cov khoom siv kho tshuab?
Cov khoom siv kho tshuab ntawm cov hlau yog txiav txim siab los ntawm lawv cov qauv me me: qhov loj ntawm cov noob, hom thiab tus lej ntawm cov theem, kev faib tawm ntawm cov av noo, thiab qhov muaj cov qhov tsis zoo ntawm cov siv lead ua xws li kev tawg. Cov khoom sib xyaw ua ke cuam tshuam rau cov khoom no los ntawm ntau txoj hauv kev tseem ceeb:
1. Kev txhim kho cov kua khov kho
Cov atoms ntawm cov khoom sib xyaw ua ke tuaj yeem hloov cov atoms hlau hauv paus (hloov chaw) lossis puv qhov sib txawv ntawm cov atoms (interstitial). Qhov sib txawv ntawm qhov loj ntawm atomic thiab kev sib txuas tshuaj lom neeg ua rau muaj kev cuam tshuam ntawm cov lattice uas tiv thaiv kev txav mus los. Qhov no ua rau muaj zog thiab tawv dua, tab sis txo qis kev ua haujlwm.
2. Kev ua kom tawv thaum los nag (kev ua kom tawv thaum muaj hnub nyoog)
Hauv qee cov hlau sib xyaw, kev kho cua sov tsim cov khoom me me (piv txwv li, Al-Cu lossis Al-Mg-Si). Cov khoom no ua haujlwm ua "kev thaiv" rau kev tawg, ua rau muaj zog ntau ntxiv.
3. Ua kom muaj zog los ntawm kev tsim cov theem tawv (piv txwv li carbides, nitrides, intermetallics)
Cov khoom xws li Cr, V, W, thiab Mo feem ntau tsim cov carbides tawv hauv cov hlau. Cov theem tawv no ua rau muaj qhov nyuaj thiab tiv taus kev hnav, tab sis tuaj yeem txo qhov tawv yog tias muaj ntau dhau lossis faib tsis zoo.
4. Kev ua kom cov nplej zoo
Qee cov ntsiab lus lossis cov txheej txheem hlau uas cuam tshuam los ntawm cov ntsiab lus alloying tuaj yeem tsim cov noob zoo dua. Cov noob zoo dua feem ntau ua rau muaj zog thiab tawv dua.
5. Kev hloov pauv ntawm daim duab theem thiab kev kho cua sov
Cov khoom sib xyaw ua ke tuaj yeem ua kom qee theem ruaj khov, hloov qhov kub hloov pauv, thiab ua rau muaj zog tawv. Piv txwv li, hauv hlau, qhov ntxiv ntawm qee cov khoom tso cai rau martensite tsim txawm tias qhov txias tsis sai heev.
Cov nyhuv ntawm cov khoom sib xyaw rau ntawm cov hlau: cov piv txwv dav tshaj plaws
Hlau yog qhov feem ntau cov hlau sib xyaw, feem ntau vim tias kev hloov pauv me me hauv cov ntsiab lus tuaj yeem ua rau muaj kev hloov pauv loj hauv cov khoom siv kho tshuab.
1. Cov pa roj carbon (C)
Cov pa roj carbon yog cov khoom siv tseem ceeb tshaj plaws hauv cov hlau. Nws ua rau lub zog thiab qhov tawv ntxiv los ntawm kev tsim cov cementite (Fe₃C) thiab lub peev xwm los tsim cov martensite tom qab hardening.
- Lub zog & qhov nyuaj: nce nrog rau kev nce ntxiv ntawm C cov ntsiab lus.
- Kev ua siab tawv & kev tawv: feem ntau yuav txo qis thaum C siab dhau.
- Kev hnav tsis kam: nce vim yog theem nyuaj dua.
Cov hlau uas tsis muaj carbon ntau yog cov uas yoog tau yooj yim dua thiab yooj yim dua rau vuam, thaum cov hlau uas muaj carbon ntau yog cov uas nyuaj dua tab sis yooj yim dua.
2. Manganese (Mn)
Manganese ua rau lub zog ntxiv los ntawm cov kua khov thiab pab khi cov sulfur los ua MnS (txo cov kub luv luv).
- Lub zog thiab kev tawv: nce ntxiv.
- Kev tawv: tuaj yeem nce ntxiv ntawm qib nruab nrab, tab sis ntawm qib siab xav tau kev tswj hwm microstructural.
3. Chromium (Cr)
Chrome yog qhov paub zoo tshaj plaws hauv cov hlau tsis xeb, tab sis kuj siv dav rau nws lub zog thiab kev hnav tsis kam.
- Hnav tsis kam & tawv: nce ntxiv los ntawm kev tsim cov Cr carbides nyuaj.
- Kev ua kom tawv: nce ntxiv, ua rau cov ntu tuab dua tawv.
– Kev tiv thaiv xeb: nce ntxiv thaum siab txaus (feem ntau ≥ ~ 10,5% hauv stainless) vim yog kev tsim ntawm ib txheej passive ntawm Cr₂O₃.
– Kev Pheej Hmoo: cov carbides ntau dhau tuaj yeem txo qhov tawv.
4. Nickel (Ni)
Nickel yog ib qho khoom siv ua kom tawv zoo heev, tshwj xeeb tshaj yog thaum kub tsawg.
- Kev tawv thiab ductility: nce ntxiv, pab tiv thaiv kom tsis txhob tawg yooj yim.
- Lub zog: nce ntxiv thaum tswj hwm qhov ruaj khov zoo.
- Daim Ntawv Thov: Ni alloy steel rau cov nkoj, cov tank cryogenic thiab cov khoom uas xav tau kev ua haujlwm siab.
5. Molybdenum (Mo)
Molybdenum yog siv dav rau kev siv kub siab thiab tiv taus kev mos.
- Lub zog ntawm qhov kub siab: nce (zoo dua creep tsis kam).
- Kev tawv: nce ntxiv.
- Kev tiv thaiv kev kub hnyiab: Mo tuaj yeem pab txo qhov kev nyiam kub hnyiab tom qab tempering ntawm qee qhov kub thiab txias.
6. Vanadium (V), Niobium (Nb), Titanium (Ti)
Cov khoom siv micro-alloying no ua tau zoo txawm tias nyob rau hauv qhov concentration tsawg. Lawv tsim cov carbides / nitrides zoo thiab ua kom cov noob zoo.
- Lub zog tawm los: nce ntxiv los ntawm cov av noo zoo thiab kev ua kom zoo ntawm cov noob.
- Kev ruaj khov: tuaj yeem ua tau zoo yog tias kev tswj hwm cov txheej txheem tsim nyog.
- Daim Ntawv Thov: HSLA (High Strength Low Alloy) hlau rau cov qauv.
7. Silicon (Si)
Silicon yog ib qho deoxidizer dav dav thiab tseem ua kom cov tshuaj khov kho.
- Lub zog: nce ntxiv.
- Kev tiv thaiv rau oxidation: nce ntxiv nyob rau hauv qee qhov xwm txheej.
- Lus Cim: cov Si ntau tuaj yeem cuam tshuam rau kev ductility thiab kev muaj peev xwm tsim.
Cov nyhuv ntawm cov khoom sib xyaw rau ntawm cov hlau txhuas
Aluminium teb tau zoo heev rau kev ua kom cov nag los ua kom muaj zog. Yog li ntawd, cov khoom siv alloying tseem ceeb, Al, yog tsim los ua cov nag me me los ntawm kev kho cov kua thiab kev laus.
- Tooj liab (Cu): ua rau muaj zog siab (2xxx series) los ntawm kev nag lossis daus, tab sis kev tiv thaiv corrosion yuav txo qis.
– Magnesium (Mg): ua rau muaj zog thiab tiv taus xeb; ua ke nrog Si tsim Mg₂Si (6xxx series) uas sib npaug zog thiab kev ua haujlwm tau zoo.
- Zinc (Zn) + Mg (thiab feem ntau yog Cu): tsim cov hlau alloys muaj zog heev (7xxx series), nrov hauv aerospace, tab sis qee cov khoom sib xyaw ua rau muaj kev ntxhov siab corrosion cracking (SCC) thiab xav tau kev tswj cua sov thiab kev tiv thaiv.
- Silicon (Si): pab txhawb kev muaj peev xwm casting thiab, nrog Mg, txhawb nqa kev nag.
Hauv txhuas, lub zog ntxiv feem ntau yog "them rau" los ntawm kev txo qis ductility, nrog rau kev rhiab heev rau corrosion hauv qee qhov kev sib xyaw ua ke.
Cov nyhuv ntawm cov khoom sib xyaw rau cov tooj liab thiab titanium alloys (ib qho kev pom)
Hauv cov hlau tooj liab, qhov ntxiv Zn (tooj dag) ua rau muaj zog thiab ua tau yooj yim dua, thaum Sn (tooj dag) ua rau muaj kev tiv thaiv kev hnav thiab qee qhov kev tiv thaiv kev xeb. Txawm li cas los xij, cov khoom sib xyaw siab dua feem ntau txo qis kev ua hluav taws xob / thermal conductivity - qhov kev cuam tshuam tseem ceeb hauv cov khoom hluav taws xob.
Hauv cov titanium alloys, cov ntsiab lus xws li Al ua rau theem alpha ruaj khov, thaum V thiab Mo ua rau theem beta ruaj khov. Alpha-beta alloys (piv txwv li, Ti-6Al-4V) muaj kev sib xyaw ua ke ntawm lub zog siab, kev tawv, thiab kev tiv thaiv corrosion, nrog rau qhov hnyav tshwj xeeb qis. Cov khoom siv kho tshuab ntawm titanium nyob ntawm cov theem tsim thiab kev kho cua sov.
Kev sib raug zoo ntawm cov khoom sib xyaw thiab cov khoom siv kho tshuab tseem ceeb
Nov yog cov ntsiab lus ntawm kev sib raug zoo uas feem ntau ntsib:
- Lub zog tensile / lub zog yield: feem ntau nce nrog cov khoom khov, nag lossis daus, cov noob zoo, thiab cov theem tawv.
- Qhov nyuaj: nce nrog martensite (hauv hlau), precipitates, thiab carbides / nitrides.
– Kev tawv: feem ntau txo qis thaum lub zog/kev tawv nce ntxiv, tab sis cov ntsiab lus xws li Ni tuaj yeem tswj tau qhov tawv.
- Kev cuam tshuam tawv: cuam tshuam los ntawm qhov loj ntawm cov noob, kev faib tawm ntawm cov khoom tawv, thiab qhov muaj cov khoom suav nrog; Ni thiab kev ua kom cov noob zoo dua qub feem ntau pab tau.
- Kev tiv taus qaug zog: nce nrog cov qauv microstructure zoo sib xws, cov khoom me me, thiab lub zog nce ntxiv; txawm li cas los xij, cov av noo / microcracks tuaj yeem zuj zus tuaj.
- Hnav tsis kam: nce nrog cov carbides tawv, martensite thiab qhov nyuaj ntawm qhov chaw zoo.
Kev kaw
Cov khoom siv alloying yog cov "cuab yeej engineering" tseem ceeb hauv metallurgy rau kev kho cov khoom siv kho tshuab ntawm cov hlau kom haum rau cov kev xav tau ntawm daim ntawv thov. Los ntawm kev xaiv hom thiab kev sib sau ua ke ntawm cov ntsiab lus, thiab tom qab ntawd tswj cov txheej txheem xws li kev kho cua sov, quenching, thiab kev tswj hwm microstructural, cov engineers tuaj yeem tsim cov ntaub ntawv uas sib dua tab sis muaj zog, tawv tab sis tawv, lossis hnav-resistant thiab ua haujlwm ntawm qhov kub siab. Txawm li cas los xij, txhua qhov kev txhim kho hauv cov khoom feem ntau los nrog kev pauv pauv: kev nce zog tuaj yeem txo qhov ductility, nag lossis daus-strengthening tuaj yeem ua rau muaj kev pheej hmoo ntawm qee qhov xeb, thiab cov theem hardening tuaj yeem txo qhov tawv yog tias tsis tswj hwm. Yog li ntawd, kev tsim alloy yeej ib txwm yog qhov sib npaug ntawm cov khoom sib xyaw, cov txheej txheem, thiab kev ua haujlwm hauv thaj teb.
