Cov pa roj carbon hlau tsis zoo yog tshwm sim los ntawm cov khoom siv, cov txheej txheem thiab kev ua haujlwm hauv cov pa roj carbon steel smelting thiab dov (forging) txheej txheem, nrog rau cov caws pliav, tawg, seem seem, txheej txheej, cov ntsiab lus dawb, kev sib cais, tsis yog xim hlau inclusions, xws li pob txha thiab banded.

Scarring

Tsis muaj caws pliav thiab lub hauv paus steel nto weld hlau lossis metalloid caws pliav blocks.Qee qhov ntawm lub cev txuas nrog lub hauv paus, yog tus nplaig;lwm tus tsis txuas nrog lub matrix, scaly.Cov tom kawg yog qee zaum tawm thaum lub sijhawm ua, tsim cov pits.Hlau (cam khwb cia) caws pliav tshwm sim los ntawm caws pliav feem ntau muaj qis dua uas tsis yog xim hlau suav nrog pom ntawm qhov muag liab qab.Scarring tsis xws luag cuam tshuam ncaj qha rau qhov zoo thiab cov tsos ntawm cov khoom siv ntawm cov hlau.Scarring tsis pub nyob rau hauv lub xub ntiag ntawm cov hlau tiav.Scarring tuaj yeem sib tsoo qhov chaw rau kev kho tom qab kho steel sib tsoo loj yuav tsum ua tau raws li tus qauv yuav tsum tau ua.

Txhaum

Cov kab nrib pleb tsim los ntawm cov duab thiab lub npe ntau yam, xws li tawg, tawg tawg, tawg, tawg, kab plaub hau, tawg (nrov tawg), rattle (Jiao tawg), dov thiab shear tawg bifida.Los ntawm kev tsim cov hlau, dov rau hauv kev ua hlau yuav luag txhua qhov txheej txheem muaj qhov ua rau tawg.

Residual shrinkage

Lub molten hlau thaum lub sij hawm solidification, vim lub ntim shrinkage nyob rau hauv lub ingot los yog billet tsis tau txaus nyob rau hauv lub central feem tsim los ntawm ib tug tubular los yog dispersion qhov.Ua ntej thermal ua, vim hais tias txiav lub taub hau me dhau los yog craters ntxaum, ua rau qhov kawg resection, qhov seem seem hu ua residual shrinkage.Cov residue tau muab faib rau hauv lub shrinkage ntawm lub Upper centre ntawm lub ingot, thiab lub ingot los ntawm sab saum toj yog hu ua cratering.

Stratified

Kev khi thiab tsis tshwm sim ntawm ob txheej txheej ntawm cov hlau substrate.Stratification feem ntau sib npaug mus rau qhov chaw ua haujlwm siab, nyob rau hauv longitudinal seem transverse dub kab yog qhov tsawg magnification specimen.Cov kab nrib pleb hnyav tshwm sim hauv cov pob txha pob txha zoo li muaj hlau, tsis yog hlau suav nrog thiab cov khoom sib cais hnyav.Tua steel ingot ingot boiling craters thiab qhov kawg ntawm lub zais pa thiab dov (forging) tsis tuaj yeem welded ua ke los tsim stratification.Kev suav loj hauv cov hlau thiab tuaj yeem tsim kev sib cais hnyav.Cov txheej txheem tsis raug tso cai hauv cov hlau tsis xws luag cuam tshuam rau kev siv hlau.

Dawb Point

Ntawm steel ntsug, cross-sectional acid leaching xeem daim, tsis muaj txoj cai sib txawv lengths hairline.Nws yog lub sij hawm tsawg nyob rau hauv cov transverse specimen radial, concentric los yog irregularly faib, multi-center, los yog los ntawm cov hlau nto muaj ib tug tej yam kev ncua deb.Hlau tawg nyob rau hauv transverse los yog longitudinal, ncig los yog oval dawb highlights.Qhov nruab nrab txoj kab uas hla ntawm 3 ~ 10mm.Hlau phaj nyob rau hauv lub longitudinal, transverse puas tus yam ntxwv dawb me ntsis yog tsis pom tseeb, tab sis lub fracture nthuav qhia rau sawb los yog oval-zoo li tus dawb me ntsis nyob rau hauv z.Thaum siv cov pob txha kuaj xyuas cov pob dawb, nws yog qhov zoo tshaj rau thawj quenched specimens thiab quenched.

Kev cais

Cov hlau tsis sib xws.Qhov tshwm sim no tsis yog tsuas yog cov khoom sib xws (xws li cov pa roj carbon, manganese, silicon, sulfur, phosphorus) tsis sib xws, tab sis kuj muaj cov khoom siv tsis yog hlau thiab cov roj faib sib xws.Yog vim li cas yog qhov sib cais tshwm sim thaum lub sij hawm solidification ntawm molten steel, lub resulting crystals separators.Feem ntau txuam nrog cov degree ntawm kev sib cais ingot, steel, smelting thiab casting ua hauj lwm tej yam kev mob.Alloying cov ntsiab lus, cais cov impurities thiab gases, nrog rau qhov kub thiab txias casting, qhov hnyav dua qhov kev sib cais.Txawm tias cov hlau siv electromagnetic stirring tuaj yeem txo qhov degree ntawm kev sib cais.Tsis tas li ntawd, kev ua kom huv ntawm steel yog qhov tseem ceeb rau kev txo qis kev sib cais.

Non-metallic inclusions

Cov hlau muaj cov khoom siv hlau thiab cov substrate sib txawv cov ntaub ntawv nonmetallic.Nws rhuav tshem cov khoom txuas ntxiv thiab isotropic ntawm cov hlau matrix.Raws li lub hauv paus ntawm non-metallic inclusions yuav muab faib ua endogenous inclusions, txawv teb chaws inclusions thiab lawv mixs.Endogenous inclusions yog deoxidation thiab ntau lub cev thiab tshuaj cov tshuaj tiv thaiv ua los ntawm kev tsim cov muaju, feem ntau steel oxygen, sulfur, nitrogen, thiab lwm yam khoom nrog cov tshuaj tiv thaiv cov khoom.

Lov

Tsis ntom thermal etching phenomenon steel seem cov ntaub so ntswg.Thermal etching ntawm steel cross-section specimen, muaj ntau qhov pores thiab dub specks txhawb nqa, rendering qhov tshwm sim yog tsis ntom cov ntaub so ntswg, hu ua xoob thaum ib tug ntawm cov pores thiab dub specks faib thoob plaws hauv lub sub-test daim, concentrated nyob rau hauv nruab nrab ntawm qhov chaw hu ua osteoporosis.Thermal etching nyob rau hauv lub longitudinal specimens pom xoob kab txaij ntawm txawv lengths, tab sis ceev faj soj ntsuam los yog soj ntsuam nrog 8 mus rau 10 lub sij hawm magnifying iav, striped tsis tob.Porosity tau soj ntsuam los ntawm kev tshuaj ntsuam xyuas electron microscopy los yog streaks tuaj yeem pom cov dendrites tsis muaj ntog nta hlau muaju.

Banded

Tom qab thermal ua ntawm cov hlau tsis tshua muaj carbon steel, lub microstructure ntawm ferrite thiab pearlite thaum uas tig mus rau dov kev taw qhia, zonal faib, tsim steel banded qauv.Banded qauv yog qhov tseem ceeb ntawm cov ntaub so ntswg tsis sib xws, kev cuam tshuam cov khoom ntawm cov hlau, tsim cov khoom siv rau kev sib deev.Banded qis steel ductility, toughness thiab txo qis, tshwj xeeb tshaj yog cuam tshuam rau cov khoom siv hluav taws xob transverse.