基于数值模拟的大型Zr-4合金铸锭锻造工艺优化

Optimization of forging process for large Zr-4 alloy ingot based on numerical simulation

锻造工艺设计是核级锆合金制造的难点之一,也是获得高质量产品的关键。针对大型Zr-4合金铸锭加工,运用Simufact-forming软件对锻造过程进行数值仿真,对比模拟和实际锻造棒料表面的温度结果,结合锻后金相组织显微观察,分析了不同加工温度对最终锻坯微观组织的影响规律。结果表明：与传统的β相区锻造工艺获得的组织相比,优化后低温高α相区锻造工艺下的锻坯内、中、外晶粒尺寸明显细小;锻造数值模拟结果和实际锻造试验结果基本吻合,对锻前的工艺设计和锻造组织的形成机理,有限元数值模拟技术均能起到很好的辅助分析作用,表现出较高的工程应用价值。

Forging process design is one of the difficulties in the manufacture of nuclear grade zirconium alloys,and it is also the key to obtain high quality products. For the processing of large-scale Zr-4 alloy ingots,Simufact-forming software was used to simulate the forging process. Comparison of the simulation and actual temperature results for forging bar surface,combined with the microscopic observation of metallographic structure after forging,the influence laws of different processing temperatures on the microstructure of final forging billet were analyzed. The results show that compared with the microstructure obtained by the traditional forging process in β phase region,the grains size of forged billet under the optimized low temperature and high α phase zone is obviously smaller. The results of numerical simulation are agreed well with the results of actual forging test. The process design before forging and the forming mechanism of forging structure can be analyzed by finite element numerical simulation technology well. Thus,the numerical simulation technology can play a very good role in auxiliary analysis and has a high value to engineering application.