Comparison of Creep Fracture Behavior Between Selective Laser Melted and Forged Alloy 230 After Testing at 1200 °C

• Published in: Metals and materials international Vol. 29; no. 5; pp. 1346 - 1357
• Main Authors: Zeng, Yijiang, Pan, Yu, Wang, Ning, Chen, Jian, Cai, Xianhui
• Format: Journal Article
• Language: English
• Published: Seoul The Korean Institute of Metals and Materials 01.05.2023; Springer Nature B.V; 대한금속·재료학회
• Subjects: Alloys; Characterization and Evaluation of Materials; Chemistry and Materials Science; Creep strength; Crystal defects; Damage tolerance; Engineering Thermodynamics; Grain boundaries; Grain size; Heat and Mass Transfer; Heat resistant alloys; High temperature; Laser beam melting; Lasers; Machines; Magnetic Materials; Magnetism; Manufacturing; Materials Science; Metallic Materials; Microstructure; Precipitates; Processes; Solid Mechanics; Stresses; 재료공학; Selective laser melted and forged alloy 230; Creep fracture behavior; Microstructure; Creep strength and life
• ISSN: 1598-9623; 2005-4149
• DOI: 10.1007/s12540-022-01313-6

The creep fracture behavior between selective laser melted (SLMed) and forged alloy 230 after testing at 1200 °C under different applied stresses was compared. The results showed that both the creep behavior of SLMed and forged alloy 230 followed the power law and obeyed the Monkman–Grant relation. The SLMed samples parallel to the building direction exhibited superior creep resistance than those perpendicular to the building direction, and the forged samples were in between, while they all exhibited poor creep ductility compared with that of the forged samples. Furthermore, the relations of applied stress and maximum allowable creep lifetime could be built to evaluate the creep resistance of the alloys. The SLMed samples parallel to the building direction showed discrete trans/intergranular cracks, while those perpendicular to the building direction and forged materials depicted continuous and discrete intergranular cracks, respectively. Furthermore, the creep fracture modes at different loadings were revealed by correlating the creep damage tolerance factor with the fractured microstructure. In addition, the effects of the initial microstructure characteristics, such as grain morphology, grain boundaries, grain size, internal defects and precipitates, on the creep strength and life at high temperatures were presented and analyzed. Graphical Abstract In order to investigate the creep fracture behavior of selective laser melted (SLMed) and forged alloy 230 at high temperatures, the differences in microstructure, cracks and fracture modes of them after testing at 1200 ℃ under different applied stresses were compared. The SLMed samples parallel to the building direction showed discrete trans/intergranular cracks, while those perpendicular to the building direction and forged materials depicted continuous and discrete intergranular cracks, respectively. Furthermore, the creep fracture modes at different loadings were revealed by correlating the creep damage tolerance factor with the fractured microstructure. The optical microstructure of creep ruptured alloy 230: (a) the SLMed samples parallel to the building direction, (b) the SLMed samples perpendicular to the building direction, (c)forged (White and red arrows refer to the building and loading directions, respectively).