Transverse Rupture Strength of the High Speed Steel Produced by Means of Powder Forging

Abstract

A study of the mechanical properties of a high speed steel, JIS SK H-2, made by powder forging and conventional processes has been carried out by transvere rupture test, hardness test and both optical and electron microscopies.
The results are as follows;
1) The strength of powder forged steel depended upon particle size, sintering temperature and pressure.
2) Apparent density of gas atomized powder is higher than that of water atomized powder.
3) Compressibility of water atomized powder is higher than that of gas atomized powder.
4) The optimum sintering temperature range is between 1200°C and 1300°C and the holding time is 1hr.
5) Transverse rupture strength of powder forged steel is 17% higher than that of commercial steel.
6) Carbide distribution of powder forged steel is fine and uniform, but that of commercial steel is banding structure.