Raws li peb paub, qhov siab dua cov ntsiab lus ntawm cov hlau, nws nyuaj dua. Thaum carbon ntxiv rau hlau, hlau carbide yog precipitated. Raws li cov ntsiab lus carbon nce, tus nqi hydrogen shrinkage nce, thaum hydrogen diffusion tus nqi txo qis. Kev tswj xyuas zoo ntawm carbides hauv microstructure yog qhov tseem ceeb thaum siv cov pa nruab nrab lossis siab carbon steel rau cov khoom thiab cov ncej. Nruab nrab thiab siab carbon steels yog dav siv nyob rau hauv ntau daim ntawv thov. Rau cov kws ua haujlwm ua haujlwm, cov pas nrig nrog cov ntsiab lus carbon ntau dua yog qhov ua rau ntau qhov tawg.
Electrochemical thwmsim qhia tau hais tias anodic dissolution cov tshuaj tiv thaiv nyob ib ncig ntawm lub matrix yog ceev los ntawm Fe-C tebchaw. Qhov ntim feem ntawm cov hlau carbide nyob rau hauv lub microstructure nce qhov tsawg hydrogen overresistance ntawm carbide duplex. Qhov saum npoo ntawm cov hlau yog yooj yim los tsim thiab adsorb hydrogen. Hydrogen atoms nkag mus rau hauv cov hlau thiab qhov ntim feem yuav nce ntxiv. Thaum kawg, cov khoom tiv thaiv rau hydrogen embrittlement tuaj yeem txo qis. Qhov tseem ceeb txo qis hauv kev tiv thaiv corrosion thiab hydrogen embrittlement ntawm high-strength steel tsis tsuas yog tsim kev puas tsuaj rau cov khoom ntawm cov hlau, tab sis kuj zoo heev txwv rau daim ntawv thov ntawm cov hlau. Piv txwv li, thaum lub tsheb hlau raug rau ntau yam corrosive ib puag ncig xws li chlorides, kev nyuaj siab corrosion cracking (SCC) yuav tsum tshwm sim nyob rau hauv siab, uas yuav ua rau muaj kev hem thawj rau kev nyab xeeb ntawm lub tsheb lub cev.
Raws li cov ntsiab lus carbon nce, hydrogen diffusion coefficient txo qis thiab hydrogen solubility nce. Cov teeb meem xws li precipitates (tapping qhov chaw rau hydrophobic atoms ntawm hydrogen atoms), muaj peev xwm, thiab cov voids uas muaj cov pa roj carbon monoxide yog proportional rau cov ntsiab lus ntawm cov pa roj carbon monoxide, uas ua rau kom cov pa roj carbon ntau ntxiv, uas ua rau cov pa roj carbon monoxide inhibits hydrogen. Txij li cov ntsiab lus carbon yog proportional rau hydrogen solubility, qhov ntau dua qhov ntim feem, qhov me me ntawm hydrogen diffusion coefficient 1045 steel rod core, thiab siab dua hydrogen solubility. Hydrogen solubility kuj muaj cov ntaub ntawv hais txog diffusible hydrogen, yog li hydrogen embrittlement susceptibility siab tshaj. Raws li cov ntsiab lus carbon nce, qhov diffusion coefficient ntawm hydrogen txo qis thiab qhov chaw hydrogen concentration nce, uas yog tshwm sim los ntawm hydrogen overvoltage droplets ntawm steel nto. Cov txiaj ntsig ntawm dynamic voltage polarization test qhia tau hais tias qhov siab dua cov pa roj carbon cov ntsiab lus ntawm cov qauv, cov pa roj carbon ntau yog koom nrog hauv cathodic txo cov tshuaj tiv thaiv (hydrogen tiam) thiab cov tshuaj tiv thaiv anodic dissolution. Carbide yog siv los ua ib lub cathode nrog ib qho ntxiv ntim feem piv rau peripheral matrix nrog tsawg hydrogen overvoltage.
Cov txiaj ntsig ntawm electrochemical hydrogen penetration test qhia tau tias ntau dua cov ntsiab lus carbon thiab carbide ntim feem hauv cov qauv pas nrig, qhov me dua qhov diffusion coefficient ntawm hydrogen thiab ntau dua qhov solubility. Raws li cov ntsiab lus carbon nce, qhov kev tiv thaiv rau hydrogen embrittlement txo. Slow strain rate tensile tests paub meej tias qhov siab dua cov ntsiab lus ntawm cov pa roj carbon monoxide, qhov qis dua qhov ua rau muaj kev ntxhov siab corrosion tawg. Raws li hydrogen txo cov tshuaj tiv thaiv thiab tus nqi ntawm cov tshuaj hydrogen txhaj rau hauv cov qauv nce, cov tshuaj tiv thaiv anodic dissolution tshwm sim, ua kom nrawm ntawm kev tsim ntawm qhov chaw plam. Raws li cov ntsiab lus carbon nce, carbides precipitate hauv cov hlau. Nyob rau hauv qhov kev txiav txim ntawm electrochemical corrosion tshwm sim, muaj peev xwm ntawm hydrogen embrittlement nce. Kev tswj cov nag lossis daus thiab ntim feem ntawm carbides yog ib txoj hauv kev zoo los xyuas kom muaj kev tiv thaiv corrosion thiab hydrogen embrittlement tsis kam ntawm steel rods.
Nruab nrab carbon steel 1045 yog txwv nyob rau hauv daim ntawv thov rau automotive qhov chaw vim yog txo nyob rau hauv hydrogen embrittlement zog uas ua los ntawm corrosion nyob rau hauv aqueous daws. Qhov tseeb, qhov no hydrogen embrittlement rhiab heev yog ze rau cov ntsiab lus carbon, thiab hlau carbide (Fe2.4C / Fe3C) precipitates nyob rau hauv qis hydrogen overvoltage tej yam kev mob. Localized nto corrosion tshwm sim los ntawm kev ntxhov siab corrosion cracking los yog hydrogen embrittlement tuaj yeem raug tshem tawm los ntawm kev kho cua sov.
