Keeb kwm: Ib qho kev hloov pauv, ob lub npe
Q345 yog tus qauv qis- alloy siab- lub zog steel hauv Suav teb raws li GB/T 1591-2008. Thaum tus qauv tau hloov kho rau GB / T 1591-2018, cov txheej txheem qib tau hloov kho thiab Q345 tau hloov los ntawm Q355. Xyoo 2008 tau raug tshem tawm, yog li cov qauv tsim tshiab hauv Suav teb tau sau nyob ib puag ncig Q355, tab sis Q345 tseem muaj nyob hauv cov qauv uas twb muaj lawm, cov npe khoom lag luam thiab cov ntaub ntawv thoob ntiaj teb.
Q hauv ob lub npe sawv cev rau lub zog tawm los, thiab tus lej yog qhov tsawg kawg nkaus tawm lub zog hauv MPa ntawm lub hauv paus tuab. Tsab ntawv txuas ntxiv txheeb xyuas qhov ntsuas kub ntawm Charpy: B kuaj ntawm ntxiv 20 degrees C, C ntawm 0 degrees C, D ntawm qhov rho tawm 20 degrees C, thiab E ntawm rho tawm 40 degrees C. Tsab ntawv no zoo ib yam hauv ob tsab ntawv, uas yog ib qho kev tsis meej pem.
Yield Strength Sib piv
| Thickness (hli) | Q345B Yield (MPa) | Q355B Yield (MPa) |
|---|---|---|
| Mus txog 16 | 345 | 355 |
| Tshaj 16 txog 35/40 | 325 | 345 |
| Tshaj 35 txog 50 / 63 | 295 | 335 |
| Ntau tshaj 50 rau 100 | 275 | 315-325 nyob ntawm qib |
Ob lub ntsiab lus tseem ceeb ntawm no. Ua ntej, cov txiaj ntsig tau txais ntau tshaj plaws nyob rau hauv nruab nrab -thickness ranges. Thib ob, GB / T 1591-2018 rov txhais cov thickness tiers, yog li cov kauj ruam nyob rau hauv ob tsab ntawv tsis zoo tib yam; ib lub rooj sib piv yuav tsum hais tias tsab ntawv twg raug muab hais.
Tensile thiab Impact Requirements
Lub zog tensile ntau yam zoo tsis hloov: 470-630 MPa rau ob qho tib si Q345B thiab Q355B hauv cov tuab tuab. Qhov yuav tsum tau Charpy yog 34 J yam tsawg kawg nkaus rau qib B hauv ob qho tib si, sim ntawm ntxiv rau 20 degrees C. Ib qho kev thov rov hais dua tias Q355B kev xeem ntawm rho tawm 20 degrees C tsis raug; Qhov ntsuas qhov ntsuas kub qis dua 20 ° C yog nyob rau qib D. Yog tias qhov project xav tau qhov kub thiab txias, nws yuav tsum qhia Q355D, tsis yog Q355B.
Chemistry Hloov
| Element | Q345B (GB/T 1591-2008) | Q355B (GB/T 1591-2018) |
|---|---|---|
| Phosphorus (max) | 0.030% | 0.030% |
| Sulfur (max) | 0.030% | 0.025% |
| Carbon sib npaug CEV (max) | Tsis tau teev tseg | 0.44% (qib B) |
Qhov kev txwv qis qis thiab cov pa roj carbon sib npaug tshiab qab nthab txhim kho weldability, uas tseem ceeb rau cov phaj tuab thiab cov pob qij txha. Xyoo 2018 tseem tso cai rau kev tswj xyuas zoo ntawm niobium, vanadium thiab titanium microalloying.
Weldability thiab Fabrication
Ob qib weld tsis preheat nyob rau hauv feem ntau thicknesses hauv qab no hais txog 30 hli siv cov khoom muab tub lim xws li ER50-6 los yog E5015. Tshaj qhov tuab, lossis hauv huab cua txias, preheat ib ncig ntawm 100-150 ° C yog qhov kev xyaum zoo. CEV txwv nyob rau hauv Q355 txo qhov kev pheej hmoo ntawm hydrogen cracking nyob rau hauv hnyav seem, uas yog ib tug tswv yim yog vim li cas nyiam Q355 nyob rau hauv cov hauj lwm tshiab.
Muaj thiab Hloov
Tuam Tshoj mills tam sim no tsim Q355 raws li tus qauv siab - qib kev muaj zog, thaum Q345 tseem muaj feem ntau rau cov haujlwm qub txeeg qub teg. Q355 feem ntau raug kho raws li kev hloov pauv ncaj qha rau Q345 ntawm cov khoom sib npaug lossis zoo dua, tab sis cov qauv tsim muaj ntawv pov thawj nyob ib puag ncig Q345 chemistry yuav tsum tau kuaj xyuas qhov twg cov thickness tier ciam teb sib txawv. Rau kev txiav txim xa tawm, ob qib feem ntau tau teeb tsa rau EN S355JR lossis ASTM A572 Qib 50, txawm hais tias qhov sib npaug yuav tsum tau lees paub rau ib qhov project.
FAQ
Puas yog Q355 zoo ib yam li Q345?
Tsis raws nraim. Q355 yog qib kawm tiav hauv GB / T 1591-2018 nrog cov txiaj ntsig qis dua me ntsis thiab cov kev txwv nruj dua. Nws hloov Q345 rau kev tsim tshiab tab sis ob lub npe tsis zoo ib yam chemistry.
Puas yog Q355B yuav tsum muaj kev cuam tshuam kev ntsuas ntawm rho tawm 20 ° C?
Tsis yog. Qib B raug ntsuas ntawm qhov ntsuas kub ntxiv 20 degrees C hauv ob tsab ntawv. Kev ntsuas qis 20 degrees C yog qib D, yog li qhia Q355D thaum qis- qhov kub thiab txias yog xav tau.
Cov pa roj carbon sib npaug li cas rau Q355B?
GB / T 1591-2018 teeb tsa qhov siab tshaj plaws CEV ntawm 0.44% rau qib B, uas txhim kho weldability piv nrog 2008 tsab uas tsis muaj kev txwv rau Q345.
Q345 puas tuaj yeem hloov nrog Q355 ntawm qhov project uas twb muaj lawm?
Feem ntau yog, txij li Q355 muaj zog sib npaug lossis siab dua ntawm txhua qib tuab. Paub meej tias cov thickness tier ciam teb thiab cov ntawv pov thawj chemistry yuav tsum tau nrog tus tsim engineer ua ntej hloov.
Dab tsi yog EN thiab ASTM sib npaug ntawm Q355?
Q355 feem ntau yog piv nrog S355JR (EN 10025-2) thiab A572 Qib 50 (ASTM), nrog rau cov lus ceeb toom uas cuam tshuam qhov kub thiab txias sib txawv ntawm cov tshuab. Rau qhov tseeb daim ntawv qhia, sib piv cov Charpy thiab chemistry tables.
Vim li cas tus qauv txav ntawm Q345 mus rau Q355?
Xyoo 2018 kev kho dua tshiab tau ua raws li Suav cov qauv hlau nrog kev coj ua thoob ntiaj teb, tsa cov txiaj ntsig nominal, nruj impurity txwv thiab ntxiv weldability tswj. Cov txiaj ntsig nce kuj tseem qhia txog kev ua cov hlau niaj hnub uas ua tau zoo dua qub.
