Capsule-free hot isostatic pressing of sintered steel to full density using water atomised iron and Cr-alloyed powder consolidated by cold isostatic pressing
Journal article, 2021

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.

full density

PM steel

capsule-free hot isostatic pressing

sintering

cold isostatic pressing

Author

Maheswaran Vattur Sundaram

Höganäs

Eduard Hryha

Chalmers, Industrial and Materials Science, Materials and manufacture

Magnus Ahlfors

Quintus Technologies AB

Ola Bergman

Höganäs

Sigurd Berg

Höganäs

Lars Nyborg

Chalmers, Industrial and Materials Science, Materials and manufacture

Powder Metallurgy

0032-5899 (ISSN)

Vol. In Press

Subject Categories

Ceramics

Materials Chemistry

Metallurgy and Metallic Materials

Areas of Advance

Materials Science

DOI

10.1080/00325899.2021.1966876

More information

Latest update

8/24/2021