【摘要】：隨著全球能源危機(jī)的不斷加深,各國(guó)現(xiàn)有的能源生產(chǎn)水平已經(jīng)無法很好的滿足其國(guó)內(nèi)經(jīng)濟(jì)增長(zhǎng)的步伐,日益突出的內(nèi)部矛盾使得對(duì)于產(chǎn)能結(jié)構(gòu)的優(yōu)化成為當(dāng)前的一個(gè)緊要問題。在眾多可利用的能源中,核能作為一種清潔、高效的新型能源逐漸受到人們的追捧,本文所研究的一體化封頭為核電站中的關(guān)鍵設(shè)備,其性能質(zhì)量的高低直接決定著整個(gè)核電站能否安全高效的運(yùn)行。因此,我們有必要對(duì)此類鍛件進(jìn)行成形與成性的整體研究。本文采用實(shí)驗(yàn)操作與數(shù)值模擬相結(jié)合的方法,在建立材料物理模型的基礎(chǔ)上對(duì)一體化上封頭的成形工藝進(jìn)行了有效的探討與研究,其結(jié)果如下:經(jīng)過一系列加熱保溫實(shí)驗(yàn),確定出了SA508-3CL鋼的合理鍛造溫度范圍—1200℃至900℃,并依據(jù)實(shí)驗(yàn)結(jié)果建立了該材料的晶粒長(zhǎng)大數(shù)學(xué)模型。同時(shí),依據(jù)熱模擬壓縮試驗(yàn)得到的真應(yīng)力—真應(yīng)變關(guān)系曲線,建立了一定變形條件下的高溫流動(dòng)應(yīng)力模型與動(dòng)、靜態(tài)再結(jié)晶模型。根據(jù)材料的熱塑性變形特性,設(shè)計(jì)出了兩套成形該一體化封頭的有效鍛造工藝—胎模鍛造與拉深成形,在對(duì)兩套工藝中的工模具尺寸進(jìn)行合理設(shè)計(jì)的基礎(chǔ)上,利用有限元模擬軟件對(duì)此封頭成形過程中的塑變情況以及成形結(jié)束后的組織分步進(jìn)行了有效的研究與對(duì)比,結(jié)果如下:在成形效果方面,兩套工藝成形出的鍛件都能夠很好地滿足核電封頭的尺寸要求�？墒�,在實(shí)際生產(chǎn)中,拉深成形所需的復(fù)雜板坯需要利用旋轉(zhuǎn)工作臺(tái),通過制盆工藝來獲得,而目前適用于此類鍛件的旋轉(zhuǎn)工作臺(tái)尚未在我國(guó)各大工廠內(nèi)廣泛應(yīng)用,故拉深成形很難應(yīng)用于實(shí)際生產(chǎn)。在微觀組織方面,2套方案得到的最終平均晶粒尺寸均過于粗大,因此,對(duì)其內(nèi)部組織的控制只能依靠后續(xù)的熱處理工藝來完成。綜上,對(duì)于此類鍛件的生產(chǎn)制造,我們更傾向于采用胎模鍛造工藝來完成。
[Abstract]:With the deepening of the global energy crisis, the existing level of energy production in various countries has been unable to meet the pace of domestic economic growth, the increasingly prominent internal contradictions make the optimization of capacity structure become a critical issue at present. Among the many available energy sources, nuclear energy, as a clean and efficient new type of energy, has been gradually sought after by people. The integrated head studied in this paper is the key equipment in the nuclear power plant. Its performance and quality directly determine whether the whole nuclear power plant can operate safely and efficiently. Therefore, it is necessary for us to study the forming and formability of this kind of forgings as a whole. In this paper, the forming process of integrated upper head is discussed and studied effectively on the basis of establishing material physical model by combining experimental operation with numerical simulation. The results are as follows: after a series of heating and heat preservation experiments, The reasonable forging temperature range of SA508-3CL steel was determined from 1200 鈩，

本文編號(hào)：2484674