發(fā)布時間：2018-06-04 05:07

  本文選題：430鐵素體不銹鋼冷軋帶鋼 + 臥式連續(xù)退火爐�。� 參考：《北京科技大學》2015年博士論文

【摘要】：針對430鐵素體不銹鋼冷軋帶鋼在臥式爐內(nèi)的連續(xù)退火過程,通過實驗和數(shù)值研究,建立了其在退火過程中的溫度、組織和力學性能預測模型。在本研究中利用高溫表面氣霧冷卻實驗結(jié)果,并結(jié)合火焰爐內(nèi)對流換熱和輻射換熱的計算方法,建立了帶鋼在爐內(nèi)的溫度預測模型；采取等溫退火實驗建立了430鐵素體冷軋帶鋼的再結(jié)晶動力學和再結(jié)晶完成后的晶粒長大動力學模型；通過模擬退火實驗的方法,研究了連續(xù)退火過程中帶鋼組織和性能演變規(guī)律,并建立了430鐵素體冷軋帶鋼在連續(xù)退火過程中的屈服強度和延伸率計算模型。在上述研究成果的基礎上,基于Sheil疊加原理,將溫度、組織和性能預測模型耦合,實現(xiàn)了實際退火過程的模擬和新退火工藝的制定。綜觀本文的研究工作,主要包括以下重要研究成果： (1)基于一維導熱反問題的研究方法,搭建了高溫表面氣霧冷卻實驗平臺。針對目前廣泛使用的某型號扇形氣霧噴嘴,研究了其在高溫不銹鋼表面的沸騰換熱規(guī)律,在水流量V≤0.83×10-5m3/s的范圍內(nèi)建立了沸騰換熱熱流密度計算關(guān)聯(lián)式。該研究成果一方面可以用于退火過程中帶鋼溫度的預測；另一個方面可研究不同操控條件下氣霧噴嘴在高溫表面的冷卻能力和冷卻均勻性,為提升帶鋼氣霧冷卻的開始冷卻溫度提供重要指導； (2)針對臥式連續(xù)退火爐,建立了爐內(nèi)帶鋼的一維非穩(wěn)態(tài)導熱模型,不同爐段的的換熱過程以邊界條件的形式進行考慮。在加熱段內(nèi),利用輻射網(wǎng)絡圖法處理了帶鋼與爐氣和爐墻之間的換熱,根據(jù)經(jīng)驗公式計算爐氣與帶鋼之間的對流換熱問題。利用Holger Martin公式計算狹縫式噴氣冷卻情況下帶鋼表面對流換熱系數(shù)。利用噴霧冷卻實驗得到的關(guān)列式計算噴霧冷卻區(qū)帶鋼表面熱流。經(jīng)過實驗驗證,模擬預測得到的爐內(nèi)帶鋼溫度誤差基本在±10%以內(nèi)； (3)通過等溫退火實驗研究不同冷軋應變量條件下430鐵素體不銹鋼冷軋帶鋼的再結(jié)晶過程,并建立了Avrami再結(jié)晶動力學模型。利用等溫退火實驗,結(jié)合截線法得到了完全軟化后材料內(nèi)部的晶粒長大規(guī)律,并分析了晶粒長大過程中的織構(gòu)演變規(guī)律。利用該模型可對連續(xù)退火過程中冷軋帶鋼的晶粒尺度和軟化率/硬度進行預測； (4)利用CCT-AV-Ⅱ模擬退火試驗機,研究了連續(xù)退火過程中帶鋼的組織和力學性能演變規(guī)律。利用所得到的實驗結(jié)果,基于Hall-Peth公式,首次建立了430鐵素體冷軋帶鋼退火過程中的屈服強度和延伸率計算模型； (5)利用本文所建立的430鐵素體冷軋帶鋼在臥式爐連續(xù)退火爐內(nèi)的溫度、組織和力學性能預測耦合模型。對實際退火過程進行模擬預測,以評價實際退火過程中存在的問題,并提出解決方案。針對特定的臥式連續(xù)退火爐,制定出了適用于不同規(guī)格430鐵素體冷軋帶鋼的退火工藝和操控參數(shù)。
[Abstract]:In view of the continuous annealing process of 430 ferrite stainless steel cold rolled strip steel in horizontal furnace, the prediction model of temperature, microstructure and mechanical properties of 430 ferrite stainless steel cold rolled strip steel during annealing process was established by experiment and numerical study. In this study, the temperature prediction model of strip steel in furnace is established by using the experimental results of high temperature surface aerosol cooling and the calculation method of convection heat transfer and radiation heat transfer in flame furnace. The kinetics of recrystallization and grain growth after recrystallization of 430 ferrite cold-rolled strip steel was established by isothermal annealing experiment. The evolution of microstructure and properties of 430 ferrite cold-rolled strip during continuous annealing was studied. The model of yield strength and elongation of 430 ferrite cold-rolled strip during continuous annealing was established. Based on the above research results and based on the Sheil superposition principle, the temperature, microstructure and properties prediction models are coupled to realize the simulation of the actual annealing process and the formulation of the new annealing process. The research work of this paper mainly includes the following important research results: 1) based on the research method of one-dimensional inverse problem of heat conduction, an experimental platform of high temperature surface aerosol cooling is built. The boiling heat transfer on the surface of high temperature stainless steel has been studied for a type of fan-shaped spray nozzle which is widely used at present. The correlation formula for calculation of boiling heat flux is established in the range of water flow rate V 鈮，

本文編號：1976074