【摘要】 针对GH4169锭型逐渐增大导致铸锭开坯时的锻透性变差的问题，采用有限元模拟方法，揭示开坯过程中坯料温度、等效应变和晶粒组织的分布与演化规律，从而更加科学地设计开坯工艺。采用有限元数值模拟，研究了镦粗过程不同初始温度和变形速率对应变场和温度场的影响，并对拔长过程中不同压下速率、道次压下量、咬入量对温度场、应变场的影响进行了研究。通过对比1 000℃、1 050℃、1 100℃的等效应变，发现随着温度升高，金属变形应变量增加。对比50 mm/s、100 mm/s、150 mm/s的压下速率，发现变形速率增加导致变形抗力的增加，使材料的表面和心部应变明显增加。对比1 020℃、1 050℃、1 080℃的初始温度下的拔长过程，得到了等效应变、温度场和应变场的演变规律，其中应变的变化与镦粗过程类似，温度场和应变场的演变受到所选用拔长条件的影响。结果表明：镦粗过程中，初始温度越高材料流动性更好，变形更均匀；压下速率增加会使内部温升增加，同样会使内部应变变大。拔长时的坯料变形过程与镦粗过程类似，温度场和应变场的演变均与整个拔长过程的时间和变形热的不同而不同。更多还原

【Abstract】 In order to solve the problem that the forging penetration of the GH4169 cast ingot becomes worse as the ingot size increases during cogging, in this paper, the finite element simulation method was adopted to reveal the distribution and evolution law of the billet temperature, equivalent strain and grain microstructure during cogging, so as to scientifically design the cogging process. By means of the finite element numerical simulation, the influence of different initial temperature and deformation rate on the strain field and temperature field in the upsetting process was studied, and the influence of different reduction rate, reduction in pass and entering amount on the temperature field and strain field in the drawing-out process was also studied. The equivalent strains at 1 000℃, 1 050℃ and 1 100℃ were compared, and it was found that as the temperature increased, the amount of metal deformation strain also increased. Comparing the reduction rates of 50 mm/s, 100 mm/s, and 150 mm/s, it was found that the increase in deformation rate leads to the increase in deformation resistance, resulting in a significant increase in surface and core strain of the material. After comparing the drawing-out processes at initial temperatures of 1 020℃, 1 050℃, and 1 080℃, the evolution laws of equivalent strain, temperature field and strain field were obtained. The changes in strain were similar to those in the upsetting process, and the evolution of temperature field and strain field was influenced by the selected drawing-out conditions. The results show that during the upsetting process, the higher the initial temperature, the better the fluidity and the more uniform the deformation. The increase of the reduction rate will increase the internal temperature rise and will also enlarge the internal strain. The deformation process of billet during drawing-out process is similar to that of upsetting process, the evolution of temperature field and strain field is different from the time and heat of deformation during the whole drawing-out process.更多还原