Instrument Specialist, Cytemp Specialty Steel, Bridgeville, Pennsylvania
Pages: 14 Published: Jan 1991
High speed tool steels contain substantial amounts of carbon and carbide formers. The resulting carbides provide high hot hardness, but they also make the high speed steels difficult to form by hot working or by grinding. The benefits and difficulties of the high speed steels are both extreme in T-15, since it is one of the most highly alloyed of the high speed steels. T-15 is therefore a prime candidate for powder metallurgy techniques, because the fine, uniformly distributed carbides provided by the process greatly improve workability and grindability with no sacrifice in hot hardness. One commercial method for consolidating powder is the Consolidation by Atmospheric Pressure (CAP) process. The CAP process requires high sintering temperatures which produce a variety of carbide sizes in the finished product. A useful rating of carbide sizes was obtained from semi-automatic image analysis of T-15. Carbide ratings can be roughly correlated to grindability. Use of this rating system facilitated the determination and adjustment of necessary processing parameters to consistently produce a superior material.
powder metallurgy, tool steel, carbide size, grindability, image analysis
Paper ID: STP17268S