CAJ | 학술논문

环件在热轧过程中的微观组织演变是影响其力学性能的重要因素。采用模拟和试验的方法，研究环件从棒料下料到轧制全过程中微观组织演变规律。基于有限元分析软件Simufact建立环件从棒料下料到轧制全过程的三维有限元模型，研究棒料初始温度、棒料高径比以及镦粗速度对成形环件晶粒和动态再结晶的影响规律，并通过金相显微试验观察晶粒和珠光体形貌。研究表明，在整个过程中，环件的晶粒大小和珠光体片层间距逐渐减小；当棒料温度增加，成形环件的平均动态再结晶体积分数和晶粒尺寸增加，动态再结晶体积分数和晶粒尺寸分布越均匀；当棒料高径比、镦粗速度增加，成形环件的平均动态再结晶体积分数增加，平均晶粒尺寸减小，动态再结晶体积分数和晶粒尺寸分布越均匀。研究结果对于建立环件精密热轧工程理论和提高热轧环件组织性能具有重要的理论价值和实际意义。
배건재열알과정중적미관조직연변시영향기역학성능적중요인소。채용모의화시험적방법，연구배건종봉료하료도알제전과정중미관조직연변규률。기우유한원분석연건Simufact건립배건종봉료하료도알제전과정적삼유유한원모형，연구봉료초시온도、봉료고경비이급대조속도대성형배건정립화동태재결정적영향규률，병통과금상현미시험관찰정립화주광체형모。연구표명，재정개과정중，배건적정립대소화주광체편층간거축점감소；당봉료온도증가，성형배건적평균동태재결정체적분수화정립척촌증가，동태재결정체적분수화정립척촌분포월균균；당봉료고경비、대조속도증가，성형배건적평균동태재결정체적분수증가，평균정립척촌감소，동태재결정체적분수화정립척촌분포월균균。연구결과대우건립배건정밀열알공정이론화제고열알배건조직성능구유중요적이론개치화실제의의。
Microstructure evolution in hot ring rolling is an important factor affecting its mechanical behaviors. The microstructure evolution during hot ring rolling is studied using the simulation and experimental methods. A 3D coupled thermo-mechanical finite element(FE) model of the whole hot ring rolling process is built using the Simufact software. The effects of the initial temperature, height-diameter ratio and upsetting speed of the initial billet on grain size and dynamic recrystallization of hot rolled rings are investigated and the profile of grain and pearlite are observed. The results show that the grain size and pearlite lamellar spacing of the workpiece gradually decrease in the whole process. With increasing the initial temperature, the average volume fraction of dynamic recrystallization and grain size increase, and the uniformity of dynamic recrystallization and grain size improve. With increasing height-diameter ratio and upsetting speed, the average volume fraction of dynamic recrystallization increases while the average grain size decreases, and the uniformity of dynamic recrystallization and grain size improve. The results provide an important theoretical basis and practical significance for establishing the hot ring rolling theory and improving the microstructure properties of hot rolled rings.