Liu Qianjun, Qiu Yao, Xin Ruishan, Luo Jianbin, Ma Qingxian
Key Laboratory for Advanced Materials Processing Technology of Ministry of Education, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China.
Ansteel Beijing Research Institute Co., Ltd., Beijing 102211, China.
Materials (Basel). 2023 Jul 25;16(15):5205. doi: 10.3390/ma16155205.
The forging-healing of the internal porosity defects affects the tensile, impact and fatigue properties of heavy forgings. In the present work, the effect of deformation process on the microstructure in the joint area as well as the tensile strength, impact toughness and fatigue strength was studied experimentally. It is shown that the tensile strength is restored once the porosity defects were healed, and the impact toughness is recovered when the flat grain band is eliminated. The fatigue strength can be restored if a uniform grain structure can be achieved in both the joint area and the matrix, whereafter precipitate become the key factor affecting the fatigue strength. A complete healing of the porosity defects, a uniform grain structure in the joint area and the matrix, and a fully controlled precipitate are essential to guarantee the mechanical properties and in-service performance of the heavy forgings.
内部孔隙缺陷的锻合修复影响大型锻件的拉伸、冲击和疲劳性能。在本研究中，通过实验研究了变形工艺对接头区域微观组织以及拉伸强度、冲击韧性和疲劳强度的影响。结果表明，孔隙缺陷修复后拉伸强度得以恢复，扁平晶带消除后冲击韧性得以恢复。如果接头区域和基体都能获得均匀的晶粒组织，则疲劳强度可以恢复，此后析出相成为影响疲劳强度的关键因素。孔隙缺陷的完全修复、接头区域和基体均匀的晶粒组织以及完全可控的析出相，对于保证大型锻件的力学性能和服役性能至关重要。
