Annealing Response of Additively Manufactured High-Strength 1.2709 Maraging Steel Depending on Elevated Temperatures

• Published in: Materials Vol. 15; no. 11; p. 3753
• Main Authors: Strakosova, Angelina, Průša, Filip, Michalcová, Alena, Kratochvíl, Petr, Vojtěch, Dalibor
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 24-05-2022; MDPI
• Subjects: 3-D printers; 3D printing; Additive manufacturing; Aging; Annealing; Cooling; Dwell time; Heat treatment; High strength; High temperature; Intermetallic compounds; Intermetallic phases; Laser beam melting; Maraging steels; Martensite; Mechanical properties; Methods; Microhardness; Microstructure; Production processes; Steel; Temperature; Ultimate tensile strength; Czech Republic; Japan; TEM-analysis; elevated temperatures; annealing response; mechanical properties; maraging steel
• ISSN: 1996-1944; 1996-1944
• DOI: 10.3390/ma15113753

The present work describes the influence of different temperatures on mechanical properties and microstructure of additively manufactured high-strength 1.2709 maraging steel. For this purpose, samples produced by selective laser melting technology were used in their as-printed as well as their heat-treated state. Both samples were than exposed to temperatures ranging between 100 °C to 900 °C with a total dwell time of 2 h followed by water-cooling. The microhardness of the as-printed material reached its maximum (561 ± 6 HV0.1) at 500 °C, which corresponded to the microstructural changes. However, the heat-treated material retained its initial mechanical properties up to 500 °C. As the temperature increased, the microhardness of both the materials reduced, reaching their minimum at 900 °C. This phenomenon was accompanied by a change in the microstructure by forming coarse-grained martensite. This also resulted in a significant decrease in the ultimate tensile strength and an increase in the plasticity. TEM analysis confirmed the formation of Ni
Mo intermetallic phases in the as-printed material when exposed to a temperature of 500 °C. It was found that the same phase was present in the heat-treated sample and it remained stable up to a temperature of 500 °C.