Metal vs Steel
Hlau thiab hlau yog qhov tseem ceeb rau tib neeg, thiab lawv tau siv sijhawm ntev.
Metal
Hlau yog paub rau tib neeg lub sijhawm ntev heev. Muaj cov pov thawj los ua pov thawj txog kev siv hlau rov qab rau xyoo 6000 BC. Kub thiab tooj liab yog thawj cov hlau uas tau pom. Cov no tau siv los ua cov cuab yeej, cov hniav nyiaj hniav kub, cov mlom, thiab lwm yam. Txij thaum ntawd los, tsuas yog ob peb lwm yam hlau (17) tau pom. Tam sim no peb paub txog 86 hom hlau sib txawv.
Hlau tseem ceeb heev vim lawv cov yam ntxwv tshwj xeeb. Feem ntau cov hlau yog tawv thiab muaj zog (muaj qhov tshwj xeeb rau qhov no xws li sodium. Sodium tuaj yeem txiav los ntawm riam). Mercury yog cov hlau uas nyob hauv lub xeev ua kua. Dhau li ntawm mercury, tag nrho lwm cov hlau muaj nyob rau hauv cov khoom muaj zog, thiab nws yog ib qho nyuaj rau tawg los yog hloov lawv cov duab piv rau lwm yam nonmetal ntsiab. Cov hlau muaj qhov ci ntsa iab. Cov hlau feem ntau muaj qhov ci ntsa iab (tshwj tsis yog kub thiab tooj liab). Txij li thaum qee cov hlau muaj zog heev nrog cov pa cua zoo li cov pa oxygen, lawv yuav tau txais cov xim du thaum lub sijhawm. Qhov no feem ntau yog los ntawm kev tsim cov hlau oxide txheej. Ntawm qhov tod tes, cov hlau zoo li kub thiab platinum yog qhov ruaj khov thiab tsis muaj zog. Cov hlau yog Malleable thiab ductile, uas tso cai rau lawv siv los ua tej yam cuab yeej.
Metals yog atoms, uas tuaj yeem tsim cations los ntawm kev tshem cov electrons. Yog li lawv yog electropositive. Hom kev sib txuas ntawm cov hlau atoms hu ua metallic bonding. Cov hlau tso tawm electrons nyob rau hauv lawv cov plhaub sab nrauv thiab cov electrons tau tawg ntawm cov hlau cations. Yog li ntawd, lawv lub npe hu ua lub hiav txwv ntawm delocalized electrons. Cov electrostatic kev sib cuam tshuam ntawm cov electrons thiab cations yog hu ua metallic bonding. Cov electrons tuaj yeem txav tau; yog li ntawd, hlau muaj peev xwm ua tau hluav taws xob. Tsis tas li ntawd, lawv yog cov thermal conductors zoo. Vim yog kev sib txuas ntawm cov hlau, cov hlau muaj cov qauv txiav txim. Cov ntsiab lus melting siab thiab cov ntsiab lus kub ntawm cov hlau kuj yog vim qhov kev sib txuas ntawm cov hlau muaj zog. Ntxiv mus, cov hlau muaj qhov ntom ntom dua li dej. Cov ntsiab lus hauv pawg IA thiab IIA yog cov hlau teeb. Lawv muaj qee qhov txawv ntawm cov lus piav qhia saum toj no ntawm cov hlau.
Steel
Hlau yog ib qho hlau ua los ntawm hlau thiab carbon. Cov pa roj carbon feem pua tuaj yeem sib txawv nyob ntawm qib thiab feem ntau nws nyob nruab nrab ntawm 0.2% thiab 2.1% los ntawm qhov hnyav. Txawm hais tias carbon yog cov khoom tseem ceeb alloying rau hlau, qee cov khoom xws li Tungsten, chromium, manganese kuj tseem siv tau rau lub hom phiaj. Ntau hom thiab ntau npaum li cas ntawm cov khoom siv alloying txiav txim siab hardness, ductility thiab tensile zog ntawm steel. Alloying lub luag haujlwm yog lub luag haujlwm tswj xyuas cov qauv siv lead ua lattice ntawm cov hlau los ntawm kev tiv thaiv kev tawg ntawm cov hlau atoms. Yog li, nws ua raws li tus neeg sawv cev hardening hauv steel. Qhov ntom ntawm cov hlau sib txawv ntawm 7, 750 thiab 8, 050 kg / m3 thiab qhov no cuam tshuam los ntawm cov khoom siv alloying ib yam nkaus. Kev kho cua sov yog txheej txheem uas hloov cov khoom siv ntawm cov hlau. Qhov no yuav cuam tshuam rau ductility, hardness thiab hluav taws xob thiab thermal zog ntawm steel.
Muaj ntau hom hlau xws li carbon steel, me me steel, stainless hlau, thiab lwm yam. Hlau feem ntau yog siv rau kev tsim kho. Cov tsev, chaw ntau pob, railway lem, txuas hniav yog ob peb qhov chaw ntawm ntau qhov chaw uas siv hlau hnyav heev. Tsis tas li ntawd, lawv tau siv hauv tsheb, nkoj, dav hlau, tshuab, thiab lwm yam. Feem ntau ntawm cov khoom siv hauv tsev niaj hnub no kuj ua los ntawm cov hlau. Tam sim no feem ntau cov rooj tog kuj tau hloov los ntawm cov khoom steel.
Qhov txawv ntawm Hlau thiab Hlau yog dab tsi?
• Cov hlau yog cov ntsiab lus whereas steel yog ib qho alloy.
• Hlau feem ntau muaj hlau.
• Hlau muaj nyob rau hauv lub ntiaj teb, whereas steel yog tib neeg tsim.
