Authors:
Pelle Mellin (1), Stefan Heino (1), David Malmström (1), Oskar Karlsson (1), Birhan Sefer (1), James Shipley (2), Anders Magnusson (2), Fredrik Forsberg (3), Björn Forsgren (4), Per Waernqvist (4)
1- Swerim AB, Kista, Sweden
2- Quintus Technologies AB, Västerås, Sweden
3- Luleå University of Technology, Luleå, Sweden
4- Ringhals AB, Väröbacka, Sweden
Abstract:
Pores in PBF-LB built material, which shrink during HIP, can regrow if they are filled with argon. The aim of this paper is understanding of this phenomenon and the underlying factors. Used material for this study was PBF-LB built 316L with porosity due to argon atomization and powder not recoating properly. A density test and XCT scanning confirmed the presence of gas and lack-of-fusion pores with a wide variety of shapes and sizes. An argon test confirmed that the pores contained Ar. The material was HIPed, followed by another XCT scan, followed by several heat treatments up to 1150 °C, followed by a final XCT scan.
However, considering the XCT results, the regrowth is minimal – perhaps non-existent at these conditions. Only after the most severe conditions (10 min at 1150 °C) is something visible in the XCT images. Microscopy exposed remains of collapsed pores that initial was much larger.
DOI:
https://doi.org/10.59499/EP235765571