本文關(guān)鍵詞： 復合軋輥 臥式離心復合鑄造 溫度場 應力場 鑄造缺陷　出處：《燕山大學》2016年博士論文　論文類型：學位論文

【摘要】：離心復合鑄造是一種能夠生產(chǎn)雙層或多層復合鑄件的最簡便方法,已廣泛應用于復合軋輥、復合鋼管的鑄造。但在雙層及多層復合鑄造過程中,由于內(nèi)外層材料的不同,如何保證各層材料良好結(jié)合的工藝控制成為關(guān)鍵問題。采用傳統(tǒng)的試錯法確定工藝成本高、浪費資源,研究開發(fā)專用軟件又需要大量的基礎(chǔ)工作,使其推廣和應用受到很大限制。本文試圖利用通用有限元商用Pro CAST軟件,建立臥式離心復合鑄造的有限元模型,為實現(xiàn)離心復合鑄造過程的流場、溫度場和應力場的模擬,優(yōu)化離心鑄造軋輥鑄造工藝,提高軋輥質(zhì)量,提供一種通用、簡便的技術(shù)手段。離心鑄造過程是復合軋輥生產(chǎn)關(guān)鍵工藝階段,而商用的Pro CAST軟件在模擬臥式離心鑄造過程中存在嚴重的失真問題。為解決這一問題,本文提出根據(jù)金屬質(zhì)點的受力特點,將筒形件臥式離心鑄造化分為符合重力流動規(guī)律的流道流動和接觸旋轉(zhuǎn)鑄型后的離心流動兩部分,分別建模的方法。用該方法對臥式離心鑄造充型過程進行模型,并利用已有水力學試驗對模型進行驗證,結(jié)果表明該方法能夠?qū)崿F(xiàn)筒形件臥式離心流動的模擬。利用分段建模方法對典型筒形件(濕式汽缸套)臥式離心鑄造過程的流場和溫度場進行了模擬研究,模擬結(jié)果與實際工藝符合的較好,進一步驗證了Pro CAST模型在臥式離心鑄造流動充型和凝固過程模擬的正確性。通過模擬研究,分析了各種工藝參數(shù)對缺陷深度的影響,解決了臥式離心鑄造濕式汽缸套鑄造缺陷深度大、廢品率高的問題。在臥式離心鑄造模擬的基礎(chǔ)上,提出了軋輥復合鑄造過程模擬的Pro CAST模型。運用該模型模擬了Cr4軋輥復合鑄造整個過程中的流場、溫度場及外層模具的溫度場,并實測了鑄型對應位置的溫度和Cr4軋輥相應位置的組織結(jié)構(gòu),對比模擬結(jié)果及實驗結(jié)果,模擬結(jié)果與實驗結(jié)果相一致。通過測定外層Cr4鋼和中間層材料的力學性能,利用Pro CAST軟件建立了軋輥復合鑄造過程的應力場模型并進行了模擬,獲得了軋輥復合鑄造凝固過程的應力場和殘余應力場。對比軋輥外層實測應力,模擬結(jié)果與實測結(jié)果具有相同的分布規(guī)律。分析了影響軋輥外層與中間層間界面結(jié)合質(zhì)量因素,給出了中間層與外層能否實現(xiàn)冶金結(jié)合和結(jié)合層厚度最小的質(zhì)量判據(jù);研究了不同鑄造工藝參數(shù)條件下能夠保證全部結(jié)合的外層離心時間,以及各種參數(shù)對外層有效厚度的影響程度,給出了各因素影響外層有效厚度的主次順序為:中間層澆鑄溫度內(nèi)表面換熱系數(shù)中間層厚度涂層厚度端蓋砂材料。針對軋輥下軸頸存在縮孔的實際問題,研究了冷鐵壁厚、材料、長度和下箱砂材料等因素對下軸頸中心縮孔位置及尺寸的影響,設(shè)計了合理的工藝技術(shù),能夠完全消除了下軸頸的中心縮孔。
[Abstract]:Centrifugal composite casting is the most convenient method to produce bilayer or multilayer composite castings. It has been widely used in the casting of compound rolls and steel pipes. However, in the process of bilayer and multilayer composite casting, due to the difference of inner and outer layer materials, How to ensure the process control of the good combination of different layers of materials becomes a key problem. The traditional method of trial and error is used to determine the high cost of the process and waste of resources. The research and development of special software also needs a lot of basic work. In this paper, the finite element model of horizontal centrifugal composite casting is established by using the general finite element commercial Pro CAST software. In order to simulate the flow field, temperature field and stress field of centrifugal composite casting process, this paper attempts to establish the finite element model of horizontal centrifugal composite casting. To optimize the casting process of centrifugal casting roll, to improve the quality of roll and to provide a general and simple technical means, the centrifugal casting process is the key process stage of compound roll production. However, the commercial Pro CAST software has serious distortion problem in the process of simulating horizontal centrifugal casting. In order to solve this problem, according to the stress characteristics of metal particles, The horizontal centrifugal casting of cylindrical parts is divided into two parts: the flow of flow channel following the law of gravity flow and the centrifugal flow after contact rotating casting. The modeling method is used to model the filling process of horizontal centrifugal casting. And the model is verified by the existing hydraulic tests. The results show that this method can simulate the horizontal centrifugal flow of cylindrical parts. The flow field and temperature field of typical cylindrical parts (wet cylinder sleeve) in horizontal centrifugal casting process are simulated by the method of segmental modeling. The simulation results are in good agreement with the actual process, which further verifies the correctness of the Pro CAST model in the flow filling and solidification process simulation of horizontal centrifugal casting. Through the simulation study, the influence of various process parameters on the defect depth is analyzed. The problems of high defect depth and high waste rate in horizontal centrifugal casting wet cylinder liner casting are solved. On the basis of horizontal centrifugal casting simulation, The Pro CAST model of roll compound casting process simulation is put forward. The flow field, temperature field and temperature field of outer die are simulated by using this model in the whole process of Cr4 roll compound casting. The temperature of the mould and the structure of the Cr4 roll are measured. The simulation results are in good agreement with the experimental results. The mechanical properties of the outer Cr4 steel and the interlayer material are measured. Using Pro CAST software, the stress field model of roll compound casting process is established and simulated. The stress field and residual stress field in the solidification process of roll compound casting are obtained. The simulation results have the same distribution law as the measured results. The factors affecting the interface bonding quality between the outer layer and the middle layer are analyzed, and the quality criterion of whether the metallurgical bonding and the minimum thickness of the bonding layer can be realized between the intermediate layer and the outer layer are given. The effect of different casting parameters on the effective thickness of the outer layer was studied. The primary and secondary order of the factors affecting the effective outer layer thickness is as follows: the heat transfer coefficient of the inner surface of the intermediate layer casting temperature; the thickness of the intermediate layer coating sand material; the thickness of the cold iron wall is studied in view of the practical problem of the shrinkage hole in the shaft neck under the roll. The influence of material length and bottom box sand material on the position and size of the central shrinkage hole of the lower axle neck is discussed. The reasonable technology is designed to eliminate the center shrinkage hole of the lower axle neck completely.
【學位授予單位】：燕山大學
【學位級別】：博士
【學位授予年份】：2016
【分類號】：TG249.4

【參考文獻】

相關(guān)期刊論文 前4條

1 陳錫棟;楊婕;趙曉棟;范細秋;;有限元法的發(fā)展現(xiàn)狀及應用[J];中國制造業(yè)信息化;2010年11期

2 劉濤;王益群;;基于掃描法的軋輥瞬態(tài)溫度場準三維建模與仿真[J];中國機械工程;2007年04期

3 曾興旺,陳立亮,劉瑞祥;鑄鋼套筒離心鑄造充型過程數(shù)值模擬[J];熱加工工藝;2004年05期

4 孫方斌,許慶彥,柳百成,張文峰,彭尚品;大型鑄鋼件補澆工藝的凝固模擬研究[J];特種鑄造及有色合金;2000年01期

，

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