大型不等壁厚RPV上封头成形工艺及组织控制的研究
发布时间：2019-05-24 07:30
【摘要】：随着全球能源危机的不断加深,各国现有的能源生产水平已经无法很好的满足其国内经济增长的步伐,日益突出的内部矛盾使得对于产能结构的优化成为当前的一个紧要问题。在众多可利用的能源中,核能作为一种清洁、高效的新型能源逐渐受到人们的追捧,本文所研究的一体化封头为核电站中的关键设备,其性能质量的高低直接决定着整个核电站能否安全高效的运行。因此,我们有必要对此类锻件进行成形与成性的整体研究。本文采用实验操作与数值模拟相结合的方法,在建立材料物理模型的基础上对一体化上封头的成形工艺进行了有效的探讨与研究,其结果如下:经过一系列加热保温实验,确定出了SA508-3CL钢的合理锻造温度范围—1200℃至900℃,并依据实验结果建立了该材料的晶粒长大数学模型。同时,依据热模拟压缩试验得到的真应力—真应变关系曲线,建立了一定变形条件下的高温流动应力模型与动、静态再结晶模型。根据材料的热塑性变形特性,设计出了两套成形该一体化封头的有效锻造工艺—胎模锻造与拉深成形,在对两套工艺中的工模具尺寸进行合理设计的基础上,利用有限元模拟软件对此封头成形过程中的塑变情况以及成形结束后的组织分步进行了有效的研究与对比,结果如下:在成形效果方面,两套工艺成形出的锻件都能够很好地满足核电封头的尺寸要求。可是,在实际生产中,拉深成形所需的复杂板坯需要利用旋转工作台,通过制盆工艺来获得,而目前适用于此类锻件的旋转工作台尚未在我国各大工厂内广泛应用,故拉深成形很难应用于实际生产。在微观组织方面,2套方案得到的最终平均晶粒尺寸均过于粗大,因此,对其内部组织的控制只能依靠后续的热处理工艺来完成。综上,对于此类锻件的生产制造,我们更倾向于采用胎模锻造工艺来完成。
[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，
本文编号：2484674
[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，
本文编号：2484674
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