Capsule-free hot isostatic pressing of sintered steel to full density using water atomised iron and Cr-alloyed powder consolidated by cold isostatic pressing
Autor: | Eduard Hryha, Lars Nyborg, Ola Bergman, Sigurd Berg, Maheswaran Vattur Sundaram, Magnus Ahlfors |
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Rok vydání: | 2021 |
Předmět: | |
Zdroj: | Powder Metallurgy. 65:133-140 |
ISSN: | 1743-2901 0032-5899 |
Popis: | Powder metallurgy (PM) steel with enhanced density is essential for meeting the demands on high strength and high-performance applications. In this study, cold isostatic pressing (CIP) is applied for consolidating water-atomised iron and Cr-alloyed steel powder to reach about 95% densification before sintering. Additionally, the effect of the lubricant and graphite addition on the compressibility of the different base powder types was evaluated. The maximum green densities of ≈7.55 g cm−3 for iron powder and ≈7.45 g cm−3 for Cr-alloyed powder were reached after CIP at 800 MPa. The sintering at 1250°C with added graphite allowed to achieve increased densification to ≈7.60 g cm−3 for the iron and ≈7.50 g cm−3 for Cr-alloyed grades, respectively. These levels were sufficient for surface pore closure, which allowed the application of the capsule-free hot isostatic pressing (HIP) after sintering to reach full density. This approach paves the way for manufacturing large-sized PM components. |
Databáze: | OpenAIRE |
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