中南大学学报（自然科学版）2023，Vol.54Issue(11)：4306-4314,9.DOI:10.11817/j.issn.1672-7207.2023.11.009
扭转变形及退火处理对MP35N高温合金力学性能及微观结构的影响
Effect of torsional deformation and subsequent annealing treatment on mechanical property and microstructure of MP35N superalloy
摘要
Abstract
The torsional deformation and annealing treatment were carried out to regulate the microstructure and mechanical properties of MP35N alloy.In addition,the microscale mechanisms related to the mechanical behaviors were investigated.The results show that the gradient dislocation density is introduced along the radial direction during the torsional deformation.Apart from that,it can be seen clearly that not only the grains are refined but also a great number of stacking faults are induced at the surface region where the strain is maximum.The introduction of gradient structure significantly enhances the strength of sample after torsional deformation up to approximately 767 MPa,and remains considerate uniform elongation about 40%simultaneously.Subsequent annealing treatment makes no difference to the gradient structure including gradient dislocation density and grain size that were introduced during the torsional deformation.However,annealing treatment gives rise to the annihilation of a portion of dislocations in the alloy and leads to a microstructural transformation from stacking faults to nanotwins at the surface region.Considering the formation of nanotwins resulted from annealing treatment and the impact of Suzuki effect,there is a secondary-stage hardening that can partly offset the softening due to dislocation annihilation.It has been estimated that the strength provided by the secondary-stage hardening is around 76 MPa.关键词
MP35N高温合金/扭转变形/退火/梯度结构/力学性能Key words
MP35N superalloy/torsional deformation/annealing/gradient structure/mechanical properties引用本文复制引用
刘畅畅,顾及,甘斌,毕中南,宋旼..扭转变形及退火处理对MP35N高温合金力学性能及微观结构的影响[J].中南大学学报（自然科学版）,2023,54(11):4306-4314,9.基金项目
国家重点研发计划项目(2017YFA0700703) （2017YFA0700703）
国家自然科学基金资助项目(52201155,92060102) （52201155,92060102）
湖南省自然科学基金资助项目(2022JJ40588) （2022JJ40588）
中南大学研究生校企联合创新项目(2021XQLH130)(Project(2017YFA0700703)supported by the National Key R&D Program of China （2021XQLH130）
Projects(52201155,92060102)supported by the National Natural Science Foundation of China （52201155,92060102）
Project(2022JJ40588)supported by the Natural Science Foundation of Hunan Province （2022JJ40588）
Project(2021XQLH130)supported by the Graduate School-Enterprise Joint Innovation Program of Central South University) （2021XQLH130）
