Dab tsi cuam tshuam rau microalloying technology muaj nyob rau ntawm weldability ntawm Q345 hlau?
Microalloying Technology (cov ntsiab lus tseem ceeb yog NB, thiab V, muaj kev phom sij ntau dua los ntawm kev tswj hwm kev phom sij vim yog cov khoom siv tshuaj tiv thaiv kab mob. Qhov cuam tshuam ntawm microalloying yuav tsum muaj kev ntsuas tsom rau cov hom keeb thiab cov ntsiab lus, nrog rau kev siv vuam thiab lub voj voog txias). Qhia tshwj xeeb, nws tuaj yeem tshawb xyuas los ntawm kev xav hauv qab no:
1. Qhov zoo: Txhim kho Weldability los ntawm kev txo cov tshuaj tua kab mob + microstructure optimization "
Ib qho ntawm cov txiaj ntsig tseem ceeb ntawm microalloying yog tias nws tso cai rau kev txo qis hauv cov ntsiab lus carbon ntawm Q345 (thaum them nyiaj rau lub zog los ntawm kev ua kom muaj zog los nag. Cov pa roj carbon yog lub ntsiab lus tseem ceeb uas ua rau muaj kev hloov pauv hloov chaw zoo "cov pa roj carbon)" tseem txhim kho wardability. Tshwj xeeb, nws ua rau pom:
1. Txo weld txias cracking kev ua tau zoo (cov ntsiab lus zoo dua)
Weld txias tawg yog qhov tseem ceeb ua ke ntawm "Hydrogen -}} kev ntxhov siab." Microalloying mitigates qhov kev pheej hmoo no hauv ob txoj kev:
Txo cov microstructure: txo cov pa roj carbon cov ntsiab lus txo cov kev nyiam ntawm cov cua sov (pob) Phoplite (p). Piv txwv li, thaum cov pa roj carbon cov ntsiab lus los ntawm 0.20% mus rau 0.15%, qhov siab tshaj plaws ntawm lub Haz tau raug txo los ntawm 320 (nyob hauv qab no txias crack rhiab ntawm 280 HV).
Inhibiting hydrogen diffusion and accumulation: Ti and Nb combine with hydrogen in the steel (diffusible hydrogen absorbed during welding) to form stable hydrides (such as TiH₂ and NbH), reducing the diffusion of free hydrogen into the HAZ stress concentration zone and the risk of hydrogen-induced cracking. Hauv kev coj ua, qhov sib thooj hydrogen cov ntsiab lus ntawm Q345 Welded pob qij txha muaj ti tuaj yeem tswj hwm hauv qab 5 ml / 100 g (tsis muaj kev pheej hmoo ntawm hydrogen embrittlement).
2. Ua kom cov qoob loo ntau ntawm cov cua sov -} cuam tshuam cheeb tsam (Haz) thiab txhim kho kev sib koom ua ke.
Qhov kub (1300 {- 1500 degree), tshwj xeeb yog nyob rau hauv lub hauv paus ua rau muaj kev loj hlob sai (piv txwv li, qhov kev cuam tshuam rau lub zog (piv txwv li, Qhov kev cuam tshuam rau lub zog ntawm -40 Degree Degles) los ntawm 50J). Microalloying Cov Ntsiab Lus Cog Lus Gragin los ntawm "pinning" thaj tsam nplej.
Ti lub luag haujlwm: Ti thiab nitrogen frect tin nanoparticles (uas muaj lub ntsiab lus melting ntawm txog li 2950℃thiab yog insoluble ntawm siab vuam txias). Cov lus no ua zoo li "rau tes" pinning cov kab ke ntawm cov qoob loo uas tsis muaj qoob loo thiab ua kom muaj qoob loo loj hauv cov pa sib dhos 100μm rau 30-5050μm. Muaj nuj nqi ntawm NB: NB qee cov yaj nyob hauv austenite hauv qhov kub thiab precipitates thaum cua txias, txuas ntxiv inhibiting nag kev loj hlob thiab ua rau nag los ntawm cov nplua-nplej nplua.
Thaum kawg, lub had kov ntawm microalloyed q345 welded pob qij txha tuaj yeem nce los ntawm 35%, xws li siv tshuab hluav taws xob tsawg (xws li kev siv tshuab thiab txuas hniav).
3. Txo Weld Porosity thiab Inclusure Distrusion
Desulfurization nyhuv ntawm Ti: Ti sib koom tes nrog cov leej faj hauv cov hlau los ua cov Tis₂ (melting taw tes 1150 degree, ntau dua li mns). Tis yog spherical (es tsis yog cov txheej txheem {3} Zoo li daim duab ntawm MNS), ua rau nws tsis tshua muaj khaub ncaws "hauv Weld Pas Dej tsis xws luag.
Kev ua kom muaj txiaj ntsig ntawm NB / V: NB thiab V tuaj yeem nqus cov pa thiab cov pa roj cares / oxides ntawm cov pa roj cares thiab kev tsim cov hws ntawm cov pa hluav taws xob) thaum lub sijhawm ua kom txias.