Cov lus piav qhia ntxaws txog kev siv loj-span truss1

Steel vaj tse yog ib tug tsis tshua muaj nqi-zoo thiab ntau yam kev daws teeb meem rau cov lag luam nyob rau hauv tag nrho cov industries.Thaum siv steel qauv vaj tse xws li steel qauv warehouses thiab steel ncej vaj tse, peb kuj yuav tsum to taub dab tsi yam cuam tshuam rau steel qauv cov ntaub ntawv.

1 、 Tshuaj muaj pes tsawg leeg

• Cov pa roj carbon:lub ntsiab tseem ceeb ntawm steel lub zog. Carbon cov ntsiab lus kev nce qib, lub zog steel kev vam meej, tab sis ua ke nrog cov yas ntawm steel, tsis kam, txias dabtsi yog khoov muaj nuj nqi, weldability thiab tsis kam mus xeb thiab corrosion yuav txo tau, tshwj xeeb tshaj yog nyob rau hauv qis kub nyob rau hauv cov kev cuam tshuam kuj yuav txo.
• Manganese thiab silicon:Cov khoom muaj txiaj ntsig zoo hauv cov hlau, yog cov deoxidizers, tuaj yeem txhim kho lub zog, tab sis tsis muaj plasticity ntau dhau thiab cuam tshuam tsis kam.
• Vanadium, niobium, titanium:alloying ntsiab nyob rau hauv steel, ob qho tib si los txhim kho lub zog ntawm cov hlau, tab sis kuj yuav tswj tau zoo heev plasticity, kuj.
• Aluminium:muaj zog deoxidizer, nrog txhuas los ua rau cov deoxidation, tuaj yeem txo cov teeb meem oxides hauv cov hlau.
• Chromium thiab nickel:alloying ntsiab los txhim kho lub zog ntawm steel.
• Sulfur thiab phosphorus:impurities tshuav nyob rau hauv cov hlau thaum lub sij hawm ce, teeb meem yam. Lawv txo cov plasticity, tsis kam, weldability thiab qaug zog ntawm cov hlau. Sulfur tuaj yeem ua rau cov hlau "kub nkig", phosphorus ua rau cov hlau "txias".
• "Hot brittle":leej faj tuaj yeem tsim kom yooj yim rau yaj hlau sulfide, thaum ua haujlwm kub thiab vuam ua kom kub txog 800 ~ 1000 ℃, kom cov hlau nthuav tawm cov kab nrib pleb, nkig.
• "Cold brittle":ntawm qhov kub thiab txias, phosphorus ua rau cov hlau cuam tshuam tsis kam txo qis hauv qhov tshwm sim.
• Oxygen thiab nitrogen:teeb meem impurities nyob rau hauv steel. Oxygen tuaj yeem ua rau steel kub nkig, nitrogen tuaj yeem ua rau steel txias nkig.

2, Kev cuam tshuam ntawm metallurgical shortcomings

Feem ntau metallurgical drawbacks muaj xws li segregation, non-metallic admixture, porosity, tawg, delamination, thiab lwm yam., tag nrho cov uas deteriorate cov hauj lwm ntawm hlau.

3. Hlau hardening

Kev kos duab txias, txias dabtsi yog khoov, xuas nrig ntaus, tshuab shear thiab lwm yam txias ua haujlwm kom cov hlau muaj qhov zoo ntawm cov yas deformation, thiab tom qab ntawd txhim kho cov ntsiab lus ntawm cov hlau, nrog rau kev poob ntawm cov yas thiab cov hlau tsis kam, qhov tshwm sim no hu ua txias hardening los yog strain hardening.

4, kub nyhuv

Hlau yog qhov tsim nyog rau qhov kub thiab txias, thiab ob qho tib si nce thiab txo qis hauv qhov kub thiab txias ua rau muaj kev hloov pauv hauv kev ua haujlwm steel. Hauv qhov sib piv, qhov ntsuas kub qis ntawm cov hlau tseem ceeb dua.

Hauv qhov ntsuas kub zoo, cov qauv dav dav yog ua raws li qhov kub thiab txias, steel lub zog txo qis, deformation nce. Txog 200 ℃ nyob rau hauv cov hlau ua haujlwm tsis hloov pauv zoo heev, 430 ~ 540 ℃ ntawm lub zog (yield zog thiab tensile lub zog) poob qis; mus txog 600 ℃ thaum lub zog qis heev tsis tuaj yeem nqa lub nra.

Tsis tas li ntawd, 250 ℃ nyob ze ntawm qhov tshwm sim xiav brittle, txog 260 ~ 320 ℃ thaum muaj qhov tshwm sim creep.