1. Cov khoom siv thiab corrosion kuj
Q: Dab tsi ua rau Hastelloy B tuab- cov yeeb nkab phab ntsa yog qhov kev xaiv zoo dua li cov qauv stainless hlau hauv cov chaw ua tshuaj lom neeg tshwj xeeb?
A: Lub ntsiab kom zoo dua ntawm Hastelloy B (tshwj xeeb yog B-2, B-3, los yog classic B alloy) nyob rau hauv nws tshwj xeeb tsis kam mus txo acids, tshwj xeeb tshaj yog hydrochloric acid (HCl) ntawm tag nrho cov concentrations thiab kub mus txog rau lub boiling point. Thaum cov txheej txheem stainless hlau (xws li 304 lossis 316) tso siab rau txheej oxide rau kev tiv thaiv (ua rau lawv haum rau oxidizing ib puag ncig), lawv ua tsis zoo rau kev txo qis.
Hastelloy B yog nickel{0}}molybdenum alloy. Nws muaj kwv yees li 26-30% Molybdenum, uas muab nws kos npe tiv thaiv kom txo cov neeg ua haujlwm. Tsis zoo li nws cov nkauj muam nraug nus, Hastelloy C (uas muaj Chromium rau oxidizing tsis kam), B alloys tau tsim tshwj xeeb los tiv thaiv qhov hnyav tshaj qhov chaw. Thaum siv rau hauv tuab- cov yeeb nkab phab ntsa, cov khoom siv no muaj kev tiv thaiv corrosion ntau heev. Qhov nce phab ntsa thickness muab cov neeg kho tshuab teeb meem thiab txuas ntxiv lub neej kev pab cuam nyob rau hauv daim ntaub ntawv uas tsis zoo corrosion, albeit tsawg, yuav tsum tau ntau xyoo. Nws kuj tseem muaj txiaj ntsig zoo rau kev ntxhov siab corrosion cracking (SCC), uas yog hom tsis ua haujlwm rau austenitic stainless hlau hauv chloride- nplua nuj, txo qhov chaw.
2. Kev tsim cov khoom sib tw thiab phab ntsa tuab
Q: Vim li cas kev tsim cov khoom tuab - cov yeeb nkab phab ntsa los ntawm Hastelloy B suav tias yog qhov nyuaj, thiab cov phab ntsa thickness cuam tshuam li cas?
A: Kev tsim cov khoom tuab- cov yeeb nkab phab ntsa hauv Hastelloy B nthuav qhia cov teeb meem loj hauv metallurgical thiab mechanical kev sib tw piv rau cov qauv carbon steel lossis lwm cov nickel alloys.
Ua ntej, ua hauj lwm hardening tus nqi. Hastelloy B alloys ua haujlwm- tawv sai. Thaum lub sij hawm tho los yog extrusion txheej txheem yuav tsum tau tsim ib tug tuab -walled seamless yeeb nkab, cov cuab yeej muaj kev nyuaj siab heev. Kev sib xyaw ua ke ntawm lub zog siab ntawm qhov kub thiab txias ceev yuav tsum muaj qhov hnyav, siab - cov khoom siv torque thiab cov cuab yeej tshwj xeeb coatings (feem ntau ceramics los yog cov carbides tshwj xeeb) los tiv thaiv galling thiab tearing.
Thib ob, thermal stability thaum tsim. Rau cov phab ntsa tuab, cov txheej txheem feem ntau yog kev sib xyaw ua ke ntawm kub extrusion ua raws li cov duab txias kom ua tiav qhov ntev. Kev tuav lub ntsuas kub tsis sib xws thaum lub sijhawm kub yog qhov tseem ceeb. Yog hais tias qhov kub thiab txias tsis sib npaug ntawm qhov tuab, nws tuaj yeem ua rau tawg vim cov hlau tsis tshua muaj ductility nyob rau hauv qhov kub thiab txias.
Thib peb, microstructural tswj. Lub thickness ntawm cov yeeb nkab phab ntsa cuam tshuam qhov txias npaum li cas tom qab kev daws annealing. Yog tias cov yeeb nkab tuab tuab (piv txwv li, teem caij 160 lossis ob npaug ntxiv hnyav) yog txias qeeb dhau, cov theem ntu nruab nrab (xws li mu theem) tuaj yeem ua rau hauv molybdenum- nplua nuj alloy. Qhov no ruins lub corrosion kuj thiab mechanical kev ncaj ncees. Yog li ntawd, cov tuam txhab lag luam yuav tsum ua kom ceev ceev quenching (dej quenching) txawm tias los ntawm cov ntoo khaub lig tuab heev - ntu kom tswj tau cov austenitic tag nrho, corrosion- cov qauv tiv thaiv.
3. Vuam thiab Fabrication raws tu qauv
Q: Yuav ua li cas cov txheej txheem vuam tshwj xeeb yuav tsum tau ua thaum koom nrog Hastelloy B tuab - cov yeeb nkab phab ntsa kom ntseeg tau qhov kev ncaj ncees ntawm vuam seam thiab cua sov- thaj tsam cuam tshuam?
A: Vuam Hastelloy B tuab- cov yeeb nkab phab ntsa yuav tsum muaj cov txheej txheem nruj vim tias cov cua kub nkag los ntawm vuam tuaj yeem rhuav tshem cov hlau ua tib zoo sib npaug. Qhov kev pheej hmoo loj tshaj plaws yog kev tsim cov theem nrab hauv cov cua sov- thaj tsam cuam tshuam (HAZ) thiab cov hlau vuam nws tus kheej, uas tuaj yeem ua rau tawg tam sim ntawd lossis nrawm nrawm hauv kev pabcuam.
Cov kev cai tseem ceeb suav nrog:
Cov khoom siv hluav taws xob qis: Cov vuam siv hluav taws xob yuav tsum siv cov txheej txheem tswj, tsis tshua muaj hluav taws xob nkag (feem ntau pulsed TIG / GTAW) kom txo qis "lub sij hawm ntawm qhov kub thiab txias" nyob rau hauv 1200℃F txog 1600℃F (650℃rau 870 degree), qhov twg carbide nag lossis daus thiab theem tsim tshwm sim.
Filler Hlau Xaiv: Rau vuam B-2 lossis B-3, cov hlau muab tub lim feem ntau yog ERNiMo-(tsim tsim nyog). Nws yuav tsum yog cov purity ntau dua los yog cov muaj pes tsawg leeg los them nyiaj rau kev sib cais thaum lub sij hawm solidification.
Interpass Temperature: Qhov no yog qhov tseem ceeb. Lub interpass kub yuav tsum tau khaws cia qis (feem ntau hauv qab 200℃F lossis 100 degree). Nyob rau tuab- cov yeeb nkab uas muaj phab ntsa, qhov no yuav tsum tau ua kom txias ntawm qhov sib txuas los tiv thaiv kev kub ntxhov.
Ncej -Weld Heat Treatment (PWHT): Tsis zoo li cov hlau, Hastelloy B feem ntau yog siv los ua -welded condition. Txawm li cas los xij, rau cov ntu tuab heev nyob rau hauv kev ntxhov siab hnyav, kev daws teeb meem annealing yuav tsum tau tom qab vuam kom rov kho dua cov theem precipitated. Qhov no yog cov txheej txheem nyuaj thiab kim vim qhov xav tau kom nrawm nrawm ntawm tag nrho cov sib dhos.
Kev huv huv: Cov khoom siv yuav tsum tsis muaj kab mob xws li roj, roj, thiab hlau. Cov hlau tsis huv tuaj yeem ua rau muaj kev cuam tshuam hauv zos. Cov kev sib tsoo tshwj xeeb (tsis muaj hlau) yuav tsum tau siv tshwj xeeb rau Hastelloy.
4. Cov ntawv thov kev lag luam tseem ceeb
Q: Koj puas tuaj yeem piav qhia txog qhov xwm txheej tshwj xeeb uas Hastelloy B tuab - cov yeeb nkab phab ntsa yog cov khoom siv tsuas yog siv tau, thiab vim li cas cov phab ntsa nyias yuav tsis txaus?
A: Ib qho piv txwv classic yog High -Hloov Hydrochloric Acid Stripper Kem hauv kev lag luam tshuaj lossis tshuaj lom neeg zoo.
Xav txog cov txheej txheem uas cov tshuaj tiv thaiv sib tov muaj chlorinated organics thiab dej. Thaum qhov kub thiab txias siab, cov tshuaj no hydrolyze los ua hydrochloric acid. Kem yuav tsum strip cov kua qaub ntawm qhov kub siab tshaj 200℃thiab siab ntawm 10-15 bar.
Vim li cas Hastelloy B? Ib puag ncig yog txo qis (kub HCl), yog li cov hlau tsis muaj hlau yuav yaj sai. Titanium tej zaum yuav raug kev txom nyem los ntawm crevice corrosion, thiab iav -kab hlau yuav tawg nyob rau hauv thermal shock los yog siab.
Vim li cas Thick Wall? Ntawm no, phab ntsa thickness pab ob lub hom phiaj:
Kev Tiv Thaiv Kev Ruaj Ntseg: Lub siab sab hauv yuav tsum muaj cov tuab tshwj xeeb kom tau raws li ASME Boiler thiab Pressure Vessel Code qhov tseem ceeb ntawm kev ntxhov siab.
Corrosion Allowance: Txawm tias nrog Hastelloy B, muaj qhov ntsuas qhov ntsuas tau ntsuas hauv mils ib xyoos (MPY). Rau ib kem tsim kom dhau 20 xyoo, engineers yuav tsum xam tag nrho cov hlau poob. Yog tias tus nqi corrosion yog 5 MPY, phab ntsa yuav tsum tuab txaus kom poob 0.1 ntiv tes ntawm nws lub neej thaum tseem tuav lub zog txaus los tuav lub siab. Lub tuab- cov yeeb nkab phab ntsa ua kom ntseeg tau tias cov khoom siv tsis ua haujlwm ntxov vim tias maj mam thinning.
5. Kev txiav txim siab thiab nqi
Q: Vim li cas Hastelloy B tuab - cov yeeb nkab phab ntsa hais kom tus nqi siab hauv khw, thiab cov neeg yuav khoom yuav ntsib teeb meem dab tsi?
A: Tus nqi siab thiab kev yuav khoom nyuaj ntawm Hastelloy B tuab- cov yeeb nkab phab ntsa yog tsav los ntawm peb yam tseem ceeb: cov nqi raw khoom, cov khoom lag luam qis, thiab kev lag luam tsis txaus.
Alloy Composition: Nickel thiab Molybdenum, cov khoom tseem ceeb, yog cov khoom kim heev LME (London Hlau Txauv) cov khoom lag luam. Cov txheej txheem alloying nws tus kheej yog lub zog- siv zog thiab yuav tsum tau tswj xyuas kom zoo.
Manufacturing Yield: Thaum ua seamless tuab - cov yeeb nkab phab ntsa, qhov piv ntawm cov khoom siv (billet) rau cov khoom tiav tuaj yeem qis. Kev tsis xws luag los ntawm cov txheej txheem tho, nto tawg, los yog ua tsis tiav hauv kev ua kom tau raws li kev ntsuas ultrasonic rau cov ntu tuab feem ntau ua rau cov khoom seem. Tus nqi ntawm cov kev ua tsis tiav no raug xa mus rau qhov kev txiav txim tiav. Tsis tas li ntawd, tsuas yog ib qho puv tes ntawm mills thoob ntiaj teb muaj cov extrusion presses muaj peev xwm tuav tau lub zog siab ntawm Hastelloy B ntawm qhov kub thiab txias.
Kev Sib Tw Sib Tw: Cov neeg yuav khoom ntsib lub sijhawm ua haujlwm ntev (feem ntau 20-30 lub lis piam lossis ntau dua) vim tias cov mills feem ntau tsim cov kav dej no ntawm ib qhov project-los ntawm- qhov project hauv paus es tsis yog khaws cia. Vim muaj kev pheej hmoo ntawm cov nag lossis daus nyob rau hauv cov ntu tuab, cov neeg yuav khoom yuav tsum tau thov kev ntsuas nruj- suav nrog kev ntsuas corrosion ntawm ib qho ASTM G28 (Txoj Kev A) thiab tag nrho cov kev kuaj xyuas ultrasonic- kom ntseeg tau tias cov khoom raug kho cua sov kom raug. Yog hais tias ib lub zeb rushes lub quench, zoo li zoo meej yeeb nkab yuav poob nyob rau hauv lub lis piam. Yog li ntawd, kev yuav khoom tsis yog hais txog tus nqi nkaus xwb tab sis hais txog kev txheeb xyuas lub zeb lub peev xwm los tswj cov khoom siv hlau tshwj xeeb ntawm cov ntu tuab.
