Transactions of Materials and Heat Treatment

Title：Microstructure simulation of typical forging process for large shaft forgings

Authors：

Unit：

KeyWords： large shaft forgings microstructure forging dynamic recrystallization numerical simulation

ClassificationCode：TG142.1+4

year,vol(issue):pagenumber：2021,46(6):33-40

Abstract：

The free forging process of large forgings has many passes and long production process, and it is impossible to verify the changes in the degree of recrystallization and grain sizes during the forging process through experiments. The 40Mn steel dynamic recrystallization model was established and verified by Gleeble thermal compression experiment. Then, the dynamic recrystallization model was used to simulate the upsetting and stretching of the typical forging process. The results show that after the second pass during stretching, most areas of forging billet occurred complete dynamic recrystallization, and the dynamic recrystallization cycle proceeds as the deformation continuous. After deformation, the average grain size in the center area of forging billet is about 117 μm, and the average grain size gradually decreases from the center to the outside. The average grain size of surface layer is about 50 μm. The average grain size changes sharply near the jaws, and the phenomenon of mixed crystal is easy to appear. The temperature near the surface of forging billet is low along the direction of nozzle, so the next round of dynamic recrystallization begins before the grains have time to grow up, so the average grain size is about 33 μm.

Funds：

国家重点研发计划(2017YFB0701801)

作者简介：孙志仁(1995－)，男，博士研究生 E-mail：17888843263@163.com 通信作者：雷丽萍(1968－)，女，博士,副研究员 E-mail：leilp@ mail.tsinghua.edu.cn

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