The Effect of the Microstructure Formed in the Forging–Healing Process on the Mechanical Properties of Heavy Forgings
Qianjun Liu,
Yao Qiu,
Ruishan Xin,
Jianbin Luo,
Qingxian Ma
Affiliations
Qianjun Liu
Key Laboratory for Advanced Materials Processing Technology of Ministry of Education, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China
Yao Qiu
Key Laboratory for Advanced Materials Processing Technology of Ministry of Education, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China
Ruishan Xin
Ansteel Beijing Research Institute Co., Ltd., Beijing 102211, China
Jianbin Luo
Key Laboratory for Advanced Materials Processing Technology of Ministry of Education, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China
Qingxian Ma
Key Laboratory for Advanced Materials Processing Technology of Ministry of Education, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China
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.