AP1000主管道冷弯壁厚减薄

Wall-thickness reduction of AP1000 primary coolant pipes subjected to cold roll-forming

提出了一种改进的Johnson-Cook模型,用于室温和低应变速率下AP1000核电站主管道316LN奥氏体不锈钢的塑性变形过程研究.借助有限元软件ANSYS/LS-DYNA,对AP1000核电一回路主管道热段管冷弯成形过程进行模拟仿真,分析管道壁厚、相对弯曲半径、摩擦系数等工艺参数对壁厚减薄率的影响规律,拟合出壁厚减薄率的经验公式.全尺寸主管道冷弯试验结果表明,数值模拟结果准确可靠.

A modified Johnson-Cook model was proposed based on the true stress-strain data of 316LN stainless steel and it was successfully used to describe the deformation characteristic of the steel at room temperature and low strain rate. By making use of the finite element software ANSYS/LS-DYNA, a numerical simulation of cold roll-forming was performed for AP1000 primary pipes. The influence laws of forming parameters on wall-thickness reduction, such as wall-thickness, relative bending radius and friction, were investigated. An empirical formula of wall-thickness reduction for AP1000 primary pipes was proposed by the numerical simulation method. Furthermore, a full-scale cold-bending experiment of AP1000 primary coolant pipes was carried out for verification, and it indicates that the simulated result is accurate and reliable.