Kev xaiv thiab zoo ntawm cov khoom siv raw rau kev tsim kho steel qauv engineering yog qhov tseem ceeb heev, uas cuam tshuam ncaj qha rau qhov zoo ntawm steel qauv engineering. Tab sis rau cov khoom siv raw, cov neeg siv feem ntau tsis to taub, niaj hnub no, peb paub qhov txawv ntawm cov khoom siv steel thiab cov qauv steel hom thiab cov lus qhia tshwj xeeb.
Yog tias koj xav ua kom muaj kev sib txawv ntawm cov hlau, tuaj yeem muaj ntau hom kev sib txawv, raws li kev siv tau muab faib ua: steel qauv, cuab yeej steel thiab steel tshwj xeeb; Raws li txoj kev smelting, nws tuaj yeem muab faib ua: Bessemer steel thiab qhib hearth steel; Raws li txoj kev deoxidation tuaj yeem muab faib ua: boiling steel (F), semi-tua steel (B), tua steel (Z) thiab tshwj xeeb tua steel (TZ); Raws li txoj kev tsim, nws tuaj yeem muab faib ua: dov steel (kub dov, txias dov), forged steel thiab cam khwb cia hlau; Raws li cov tshuaj muaj pes tsawg leeg tuaj yeem muab faib ua: carbon steel thiab alloy steel. Cov pa roj carbon steel thiab alloy steel feem ntau yog siv rau hauv kev tsim steel qauv.
Carbon structural steels tau muab faib ua tsib hom: Q195, Q215, Q235, Q355 thiab Q275. Qhov siab dua lub zog tawm los, qhov siab dua cov ntsiab lus carbon, lub zog thiab hardness, thiab cov yas qis dua. Ntawm lawv, Q235 muaj kev ua tau zoo hauv kev siv, ua thiab vuam. Nws yog feem ntau siv hlau hauv steel qauv engineering kev tsim kho, thiab carbon structural steel feem ntau siv hauv steel qauv engineering. Q235 thiab Q355 feem ntau siv hauv Suav teb.
Cov hlau tsis tshua muaj hlau yog cov uas ib lossis ntau qhov me me ntawm cov hlau alloying ntxiv thaum lub sij hawm steelmaking thiab tag nrho cov nyiaj tsawg dua 5 feem pua. Cov hlau tsis tshua muaj hlau muaj zog dua vim tias lawv muaj cov ntsiab lus alloying. Nws qib yog qhia tib yam li carbon structural steel qib. Feem ntau siv cov hlau tsis tshua muaj hlau yog Q345, Q235, Q420 thiab lwm yam, uas kuj yog ib qho ntawm cov hlau feem ntau siv hauv steel qauv engineering siv.
The above two kinds of steel are classified into grade A, B, C and D, with A to D indicating the quality from low to high. However, the quality grade of low-alloy steel is E more than that of carbon steel, with five grades. In the engineering drawings of steel structures, we will see the steel type, such as Q235B, which represents the distinction between carbon structural steels with strength, such as Q235, which represents the yield point (σ S) of 235 MPa. The steel number can be marked after it to indicate the quality grade.
