Tailoring the surface microstructure of starch consolidated vanadium-rich high speed steel powder
Paper in proceedings, 2008

The nitrogen sintering of vanadium rich high speed steel has been applied for tailoring of surface microstructure. The approach has been facilitated by thermodynamics modelling of phase equilibria, novel shaping methods like starch consolidation and various manipulations of the sintering atmosphere. It is demonstrated that elevated nitrogen sintering densification occurs when an open pore structure interacts with nitrogen slightly below the nitrogen-reduced solidus temperature. The compact can then first be pre-sintered to around 85% relative density in vacuum, and thereafter be infiltrated with nitrogen at the nitrogen-reduced solidus temperature and finally be sintered to near full density at a temperature of 10% liquid phase formation in nitrogen. The end result is a microstructure with an elevated MX transformation in the surface, whose depth depends on the carbon balance of the material.

High speed steel and starch consolidation

Liquid phase sintering

Nitrogen sintering

Vanadium

Author

Henrik Borgström

Chalmers, Materials and Manufacturing Technology, Surface and Microstructure Engineering

P. Harlin

Dalarna university

Lars Nyborg

Chalmers, Materials and Manufacturing Technology, Surface and Microstructure Engineering

European International Powder Metallurgy Congress and Exhibition, Euro PM 2008; Mannheim; Germany; 29 September 2008 through 1 October 2008

Vol. 3 289-294

Subject Categories

Materials Engineering

ISBN

978-189907203-3

More information

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4/1/2019 9