Titanium muaj ib qho kev xav zoo heev los nqus hydrogen. Hydrogen atoms tsim thaum lub sij hawm pickling descaling, vuam, cathodic tiv thaiv thiab acidic nruab nrab corrosion nkag mus rau hauv titanium matrix. Thaum hydrogen solubility ntau tshaj qhov saturation txwv, brittle titanium hydride precipitates raws lis ciam teb thiab dislocations, heev txo cov khoom plasticity thiab toughness. Nyob rau hauv lub thermal voj voog load, sib dhos kev nyuaj siab thiab nyob rau hauv nruab nrab siab, microcracks sai sprout thiab txuas mus rau hydride faib zones, uas ua rau tam sim ntawd brittle rupture ntawm lub cua sov raj yam tsis pom tseeb yas deformation. Hydrogen embrittlement yog ib qho ntawm kev puas tsuaj sai tshaj plaws rau cov khoom siv hluav taws xob titanium.
1. Micro-Mechanism ntawm Hydrogen Absorption thiab Embrittlement
Nascent hydrogen generated nyob rau hauv corrosive ua hauj lwm tej yam kev mob yooj yim dhau los ntawm nyias titanium dioxide passive zaj duab xis thiab diffuses rau hauv titanium lattice. Nrog txuas ntxiv hydrogen tsub zuj zuj, oversaturated hydrogen ua ke nrog titanium los tsim flaky, tawv thiab brittle titanium hydride theem. Lub hydride theem muaj mismatched thermal expansion thiab mechanical zog nrog titanium puag hlau, ua rau muaj kev ntxhov siab nyob rau hauv interfacial residual. Tensile stress concentrates ntawm hydride nag lossis daus qhov chaw los rhuav lub matrix thiab tsim microcracks. Cracks propagates sai raws li hydride network kom txog rau thaum nkag mus rau hauv cov yeeb nkab phab ntsa thiab ua rau to thiab tawg. Tsis zoo li stainless hlau hydrogen-induced cracking, titanium embrittlement yog dominated los ntawm hydride theem los nag thiab theem interface splitting.
2. Cov txheej txheem ua haujlwm tseem ceeb ua rau Hydrogen Ingress
Acid pickling rau oxide tshem tawm yam tsis muaj hydrogen inhibitors, ua rau hydrogen permeation loj heev;
Vuam tsis tiav argon shielding, qhov twg noo noo decomposes rau hauv hydrogen thiab invades weld hlau;
Tshaj - tiv thaiv cathodic tiv thaiv nrog ntau yam tsis zoo uas ua rau muaj kev kub ntxhov hydrogen evolution cov tshuaj tiv thaiv;
Ntev - lub sij hawm immersion nyob rau hauv hydrofluoric acid, fluoride khib nyiab thiab muaj zog acidic corrosive kua;
Muab kaw cia nrog cov dej vapor seem hauv cov hlab, uas decomposes rau hauv hydrogen nyob rau hauv cov cua kub.
3. Tej yam tseem ceeb ua rau muaj kev cuam tshuam ntawm hydrogen embrittlement
Tsis muaj dehydrogenation ci tom qab hydrogen{0}} qhia txog cov txheej txheem xws li pickling thiab vuam;
Tsis tshua muaj kev khiav hauj lwm kub hindering hydrogen khiav thiab accelerating hydride nag lossis daus;
High tensile residual kev ntxhov siab los ntawm kev khoov txias thiab ua kom qis dua qhov tseem ceeb ntawm kev tawg;
Nto khawb thiab suav nrog ua qhov tseem ceeb ntawm hydrogen aggregation txoj haujlwm;
Kev sib cuag ncaj qha nrog cov hlau sib txawv ua rau galvanic corrosion thiab ntxiv hydrogen tiam.
4. Txheej Txheem Tag Nrho -Txuas Kev Tiv Thaiv Kev Tiv Thaiv
① Ntxiv hydrogen inhibitor thaum lub sij hawm pickling txheej txheem
Siv tshwj xeeb pickling additives los txwv hydrogen ion txo cov tshuaj tiv thaiv; nruj me ntsis tswj lub sij hawm pickling los tiv thaiv tshaj -corrosion.
② Siv tag nrho ob npaug -sided argon shielding vuam specification
Cais huab cua thiab noo noo tag nrho; kom qhuav welding muab tub lim hlau ua ntej siv los tshem tawm cov khoom siv hydrogen.
③ Calibrate cathodic tiv thaiv muaj peev xwm ntau yam
Txwv tsis pub muaj kev tiv thaiv ntau dhau los txiav tawm hydrogen evolution cov tshuaj tiv thaiv ntawm qhov chaw.
④ Ua qis -kub dehydrogenation tshav kub kho
Rwb thaiv tsev workpieces ntawm 200 ~ 300℃rau lub sij hawm txaus los tsav yaj hydrogen tawm ntawm lub matrix.
⑤ Txhim kho qhov nruab nrab muaj pes tsawg leeg thiab kev sim tsis tu ncua
Txo cov fluoride thiab muaj zog acid concentration hauv cov txheej txheem kua; siv ultrasonic tshuaj xyuas ib ntus kom pom hydride-induced sab hauv tawg.
5. Kev Tiv Thaiv Cov Teeb Meem Sib piv
表格
| Txheej Txheem & Kev Pabcuam Hom | Hydrogen Embrittlement Risk | Daim ntawv thov tswv yim |
|---|---|---|
| Pickling tsis muaj inhibitor + tsis muaj dehydrogenation ci | Tsis tshua muaj kev pheej hmoo ntawm kev tawg sai sai | Kho cov txheej txheem thiab ua dehydrogenation tam sim ntawd |
| Inhibitor ntxiv + post- txheej txheem ci dehydrogenation | Yeej tshem tawm hydrogen enrichment txaus ntshai | Yuav tsum tau txheej txheem txheej txheem rau titanium qhov chaw |
| Ua kom tiav argon-shielded vuam + nruab nrab muaj pes tsawg leeg tswj | Ntev -lub sij hawm ruaj khov tiv thaiv-embrittlement kev ua tau zoo | Cov txheej txheem tseem ceeb rau fluoride- muaj cov haujlwm hnyav |
Xaus
Hydrogen embrittlement ntawm titanium cua sov raj pib los ntawm hydrogen permeation mus rau hauv matrix, nag lossis daus ntawm brittle hydride theem thiab interfacial kev nyuaj siab tawg. Cov txheej txheem tswj tseem ceeb suav nrog kev thaiv cov kab hluav taws xob tsim hluav taws xob hauv kev tsim cov txheej txheem, yuam hydrogen khiav tawm ntawm kev kho cua sov, tshem tawm tensile residual stress thiab txhim kho nruab nrab corrosivity. Kaw -Txoj kev tswj xyuas qhov chaw kho, vuam, tiv thaiv- kev tiv thaiv corrosion thiab kev tshuaj xyuas niaj hnub tuaj yeem tshem tawm cov xwm txheej tshwm sim los ntawm hydrogen embrittlement ntawm titanium cov khoom cua sov.
