The Effect of the Microstructure Formed in the Forging-Healing Process on the Mechanical Properties of Heavy Forgings

• Published in: Materials Vol. 16; no. 15; p. 5205
• Main Authors: Liu, Qianjun, Qiu, Yao, Xin, Ruishan, Luo, Jianbin, Ma, Qingxian
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 25.07.2023; MDPI
• Subjects: Analysis; Crystal defects; defect healing; Deformation; Deformation effects; Experimental methods; Experiments; Fatigue strength; Forging; Forgings; Geometry; Grain structure; Healing; heavy forgings; Impact strength; Impact tests; Influence; Mechanical properties; Metal fatigue; Microstructure; Morphology; plastic deformation; Porosity; Research methodology; Tensile strength; Test methods; Toughness; China; heavy forgings; defect healing; mechanical properties; plastic deformation
• ISSN: 1996-1944; 1996-1944
• 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.