核电主蒸汽超级管道管嘴成形有限元分析

FEA on nozzle forming for nuclear power main steam super pipeline

针对核电主蒸汽超级管道管嘴的成形工艺难点:加热工艺、管嘴挤压成形工艺,采用有限元软件ABAQUS分析了影响核电主蒸汽超级管道管嘴成形的主要因素:凸模形状、凸模高度、接触摩擦力和材料温降等。分析结果表明,凸模轮廓直接影响材料的等效塑性应变和管嘴成形尺寸;凸模高度、表面摩擦条件影响管嘴壁厚和高度变化。优化这些影响因素后,进行管嘴一次挤压成形试验,试验结果表明,采用凸形凸模、调整凸模高度、增加润滑条件和降低坯料温降,可以成形出合格的管嘴零件。

For the difficulties in nozzle forming such as heating and extrusion in the nuclear power main steam super pipeline,the major influential factors of the nuclear power main steam super pipeline forming,namely,the shape and height of the punch,the friction and temperature drop of the material and so on,were analyzed by FEA（ ABAQUS）. The analysis results show that the outline of the punch directly affects the equivalent plastic strain of the material and the size of the nozzle,and the punch height and surface friction coefficient also directly affect wall thickness and height of nozzle. After optimizing the above influence factors,the extrusion test of nozzle forming was conducted. Thus,the test results show that the required nozzle can be gained by convex punch,adjusting punch height,increasing lubrication and lowering the temperature drop of the material.