Hydrogen embrittlement yog ib qho zais nkig tsis ua haujlwm ntawm 316 stainless hlau cua sov raj. Hydrogen atoms nkag mus rau hauv cov hlau lattice thiab sib sau ua ke ntawm cov ciam teb, dislocations thiab sab hauv tsis xws luag, txo cov khoom plasticity thiab toughness sharply. Nyob rau hauv tensile kev nyuaj siab, sab hauv hydrogen siab generates microcracks uas nthuav sai heev los tsim cov pob txha pob txha. Cov yeeb nkab phab ntsa tsis muaj qhov pom tseeb corrosion thinning, thiab tam sim ntawd tawg feem ntau tshwm sim nyob rau hauv load los yog kub hloov pauv, nrog tsis tshua muaj kev kwv yees. Daim ntawv no piav qhia txog cov txheej txheem nkag mus thiab kev tiv thaiv kev tiv thaiv.
1. Core Hydrogen Embrittlement Mechanism
Nyob rau hauv acidic pickling kua, cathodic tiv thaiv thiab electrochemical corrosion ib puag ncig, hydrogen ions tau electrons los ua kom nquag plias hydrogen atoms. Cov atoms me me no tuaj yeem yooj yim dhau los ntawm cov zaj duab xis passive thiab diffuse mus rau sab hauv ntawm 316 stainless hlau. Hydrogen accumulates nyob rau hauv cov microvoids thiab grain ciam teb, combining rau hauv hydrogen molecules nrog loj ntim. Internal gas siab ua rau muaj zog tensile loj hauv cov khoom. Thaum superimposed nrog ua cov residual kev nyuaj siab, los ua ke kev nyuaj siab los yog thermal cyclic kev nyuaj siab, microcracks pib thiab propagate raws li cov yam ntxwv tsis muaj zog. Tag nrho cov txheej txheem belongs rau brittle puas; Txawm tias cov ntaub ntawv uas zoo li qub yuav dheev tawg nyob rau hauv kev cuam tshuam sab nraud, uas yog cov yam ntxwv ntawm hydrogen -induced qeeb cracking.
2. Qhov chaw tseem ceeb ntawm Hydrogen Ingress
(1) Pickling thiab pretreatment txheej txheem
Lub sij hawm pickling ntev heev thiab siab -cov kua qaub kua qaub ua rau muaj ntau cov tshuaj hydrogen. Hydrogen invades cov yeeb nkab phab ntsa thaum tshem tawm xeb thiab oxidation txheej ntxuav, tawm hauv zais embrittlement txaus ntshai.
(2) Cathodic tshuaj tiv thaiv thaum lub sij hawm kev pab cuam corrosion
Thaum lub raj cua sov ua haujlwm ua cov cathode hauv galvanic cell lossis electrochemical corrosion system, txuas ntxiv hydrogen evolution tshwm sim ntawm qhov chaw, ua rau ntev - hydrogen permeation.
(3) Welding muaj kuab paug
Cov dej vapor thiab roj impurities decompose thaum lub sij hawm vuam los tsim hydrogen, uas yaj mus rau hauv lub vuam thiab tshav kub- cuam tshuam cheeb tsam, ua welded pob qij txha feem ntau txoj hauj lwm rau hydrogen embrittlement cracking.
(4) Siab -siab hydrogen- muaj qhov nruab nrab ua haujlwm
Kev sib cuag ncaj qha nrog hydrogen- cov dej khib nyiab nplua nuj thiab cov txheej txheem nruab nrab nrawm nrawm hydrogen atom diffusion mus rau hauv lub substrate.
3. Tej yam tseem ceeb cuam tshuam uas ua rau muaj kev ntxhov siab ntau ntxiv
Tensile stress level: Qhov siab dua qhov seem tensile kev nyuaj siab los ntawm khoov thiab vuam, qhov qis dua qhov tseem ceeb hydrogen concentration rau kev tawg;
Cov khoom tsis xws luag: suav nrog, pores thiab grain ciam rhiab heev muab qhov chaw nyiam sib sau ua ke rau hydrogen;
Tsawg- qhov kub thiab txias qhov chaw: Hydrogen tag nrho nkag rau hauv cov khoom thaum lub sijhawm kaw, thiab tawg yooj yim tshwm sim tom qab rov pib cua sov;
Overlong acid soaking: Ntau ntau pickling yog feem ntau cov khoom tsim inducement hauv ntau lawm.
4. Tag nrho cov txheej txheem tiv thaiv thiab tswj kev ntsuas
① Standardize cov txheej txheem pickling tsis
nruj me ntsis txwv pickling concentration, kub thiab soaking lub sij hawm; txais yuav cov tshuaj tiv thaiv corrosion uas muaj cov tshuaj tiv thaiv hydrogen kom txo cov tshuaj tiv thaiv hydrogen evolution. Tom qab pickling, ua kom huv si yaug thiab ci dehydrogenation kom tsav tawm diffusible hydrogen hauv cov yeeb nkab phab ntsa.
② Txhim kho vuam los tiv thaiv - hydrogen ntsuas
Qhuav vuam hlau ua ntej siv kom tshem tawm cov dej noo; siv tsawg-hydrogen argon arc vuam txheej txheem; siv backside argon tiv thaiv los txo qhov pore tsis xws luag thiab hydrogen dissolution nyob rau hauv welds.
③ Tshem tawm sab hauv tensile kev nyuaj siab
Ua cov ntawv tshaj tawm- ua kom txo qis kev ntxhov siab los txo qhov kev ntxhov siab uas ua rau tawg tawg; nyiam 316L qis- cov khoom siv carbon nrog tsawg dua cov ciam teb nag lossis daus thiab muaj peev xwm ua kom tsis muaj zog hydrogen.
④ Zam kev tiv thaiv cathode tsis tsim nyog
Rau cov khoom siv cua sov hauv ib puag ncig pickling, txwv tsis pub dhau cathodic tam sim no los tiv thaiv hydrogen nag lossis daus loj ntawm stainless hlau nto.
⑤ Tom qab- txheej txheem dehydrogenation ci kev kho mob
Rau cov khoom tom qab pickling thiab vuam, tuav ntawm 200 ~ 230℃rau kev txuag cua sov kom cia diffusible hydrogen khiav tawm ntawm cov hlau lattice thiab tshem tawm ncua kev tawg zais zais kev phom sij.
5. Kev Tiv Thaiv Cov Teeb Meem Sib piv
表格
| Kev Txuas Txuas | Hydrogen Embrittlement Risk | Txoj Kev Txhim Kho |
|---|---|---|
| Uncontrolled long -lub sij hawm pickling | Siab heev | Txwv tsis pub pickling + dehydrogenation ci |
| Moisture -cov kab mob sib kis | Nruab nrab | Tsawg- txheej txheem hydrogen welding + hlau kom qhuav |
| Kev ntxhov siab - cov khoom tiav tiav + dehydrogenation | Tsis tsim nyog | Standard tiav cov khoom ua ntws |
Xaus
Peb yam tseem ceeb rau hydrogen embrittlement yog hydrogen infiltration, cov khoom siv sab hauv sib sau ua ke thiab tensile kev nyuaj siab tsav kev loj hlob tawg. Los ntawm kev txiav tawm hydrogen introduction channel nyob rau hauv pickling thiab vuam cov txheej txheem, tshem tawm cov residual kev nyuaj siab thiab teem tshwj xeeb dehydrogenation tshav kub kev kho mob, ncua nkig tawg tshwm sim los ntawm hydrogen embrittlement ntawm 316 cua sov raj tuaj yeem zam tau zoo, tshem tawm kev nyab xeeb sai sai hauv cov tshuab cua sov.
