Sulfide Stress Cracking yog ib daim ntawv ntawm hydrogen embrittlement cracking. Nws tshwm sim nyob rau hauv qis- alloy steel pipelines, siab- lub zog steels, welded pob qij txha, thiab Thaum tshav kub kub- Cov cheeb tsam cuam tshuam uas raug rau tensile kev nyuaj siab nyob rau hauv acidic ib puag ncig thiab kub hauv qab 82 degree, nyob ntawm seb cov hlau muaj pes tsawg leeg, microstructure, lub zog, residual stress, thiab lwm yam kev ntxhov siab.
Raus cov hlau phaj cov qauv hauv cov kua qaub aqueous uas muaj H₂S, thiab tau txais cov ntaub ntawv Sulfide Stress Cracking Resistance los ntawm kev siv cov khoom tsim nyog ntxiv. Raws li NACE TM0177-2016 tus qauv, cov kev xav tau tshwj xeeb yog raws li hauv qab no: Siv cov txheej txheem forged steel phaj nrog qhov siab tshaj σb lossis Hb , ua qhov kev ntsuam xyuas sulfide kev ntxhov siab tawg, thiab kev ntxhov siab σTh Ntau dua lossis sib npaug rau 247MPa yog suav tias tsim nyog. Siv ib txheej ntawm cov qauv los ntawm txhua qib A, B, thiab D welded cov qauv sib koom ua ke rau kev kuaj sulfide kev nyuaj siab tawg, thiab kev ntxhov siab σTh Ntau dua lossis sib npaug rau 247MPa yog tsim nyog.
Hydrogen-Induced Cracking yog ib qho kev tawg sab hauv nrog cov yam ntxwv ua ntu zus los ntawm kev sib txuas ntawm cov kab sib txuas hydrogen txheej txheej, tsis muaj kev cuam tshuam nrog kev ntxhov siab sab nraud lossis kev ntxhov siab seem. Ntawm qhov chaw blistering, qhov kev ntxhov siab tsim los ntawm hydrogen tsub zuj zuj nyob rau hauv intensifies hydrogen-induced cracking. HIC muaj feem xyuam nrog kev huv huv steel, kev tsim khoom, muaj cov impurities, thiab lawv cov duab.
HIC tshwm sim nyob rau hauv nyias, heterogeneous sulfide los yog oxide inclusions parallel rau steel phaj dov kev taw qhia. Cov inclusions no tsim cov chaw nucleation rau microhydrogen npuas, uas nws thiaj li loj hlob ua ke los ntawm cov pob txha tawg. Txij li HIC yog kev ntxhov siab- ywj pheej thiab tsis tshwm sim hauv cov qauv tawv, tom qab-weld kev kho cua sov tsis muaj qhov tseem ceeb. Kev tawm tsam rau hydrogen-induced cracking tsuas yog ua tiav los ntawm kev txwv cov kab sulfur thiab tswj cov khoom tsim steel.
Kev xeem SSC thiab HIC yog raws li NACE International xeem cov qauv pom zoo los ntawm American Society of Corrosion Engineers. Kev xeem SSC feem ntau yog siv tas li -Load stress corrosion test thiab peb-point dabtsi yog khoov xeem, feem ntau raws li tus qauv NACE TM0177; Kev xeem HIC feem ntau ua raws NACE TM0284 tus qauv. Rau cov khoom siv hauv kev tsim thiab tsim cov qauv tsim elastic, cov neeg ua raws li ISO 15156-2, ISO 15156-3, lossis NACE MR0175 cov qauv tuaj yeem xaiv. Cov qauv no qhia ib puag ncig tej yam kev mob kom tsis txhob muaj kev ntxhov siab corrosion. Tsuas yog cov ntaub ntawv ua tau raws li cov kev txwv no yuav tsum tau siv.
Cov xwm txheej rau Carbon Steel, Tsawg-Alloy Steel, thiab Cam khwb cia hlau kom raug zam los ntawm SSC thiab HIC Tests
Cov ntaub ntawv yuav tsum raug xa mus rau hauv cov xwm txheej hauv qab no: Kub- dov /annealed / normalized / normalized + tempered / austenitized, quenched + tempered / austenitized, quenched + tempered
Khoom hardness Tsawg dua los yog sib npaug rau 22HRC, cov ntsiab lus nickel<1.0%;S ≤0.003%, P ≤0.010%;The hardness of welds and heat-affected zones shall not exceed 22HRC.
Cov khoom muaj zog yield<355MPa, tensile strength <630MPa
Carbon sib npaug txwv: Tsawg- carbon steel thiab carbon-manganese steel: Ce Less dua los yog sib npaug rau 0.43 (Ce=C + Mn/6) Tsawg- alloy steel: Ce Tsawg dua los yog sib npaug rau 0.45 (Ce== C + 1} + Cr + Mn/ V)/{13}} (Ni + Cu)/15)
Cov xwm txheej rau Stainless Hlau kom raug zam los ntawm SSC thiab HIC Tests
Chemical Composition Limits
321 stainless hlau nrog cov ntsiab lus siab dua cov pa roj carbon monoxide tau tso cai ntxiv lwm cov ntsiab lus hauv cov khoom siv sib xws.
Kev daws annealing quenching lossis annealing cua sov stabilization txheej txheem kev kho cua sov yuav tsum tau txais yuav;
Kev ua haujlwm txias los txhim kho cov khoom siv kho tshuab tsis raug tso cai;
Lub hardness ntawm raw cov ntaub ntawv, welds, thiab cua sov- thaj tsam cuam tshuam yuav tsum tsis pub tshaj 22HRC.
