Effects of inclusions and tempering temperature on the life of a powder compacting punch

✍ Scribed by Seong-Hyeon Hong; Jong-Soo Bae; Yong-Jin Kim

• Publisher: Elsevier Science
• Year: 2003
• Tongue: English
• Weight: 450 KB
• Volume: 10
• Category: Article
• ISSN: 1350-6307
• DOI: 10.1016/s1350-6307(02)00045-6

✦ Synopsis

Effects of nonmetallic inclusions and tempering temperature on the mechanical properties and failure life of the powder metallurgical (P/M) high-speed steel (1.28% C, 4.20% Cr, 6.40% W, 5.00% Mo, 3.1% V, bal. Fe) were investigated. Small amounts of non-metallic inclusions in the specimen did not greatly affected impact energy and transverse rupture strength (TRS). But, failure lives of the three point bend fatigue specimens and powder compacting punch were drastically decreased by crack initiation around non-metallic inclusions under the cyclic load. On the other hand, as tempering temperature increased, the volume fraction and average size of carbides (MC or M 6 C) did not significantly change, while hardness of specimen decreased. The failure lives of the three point bend tested specimens and powder compacting punch drastically increased with increasing tempering temperature due to increased resistance to fatigue crack propagation by the softening of the matrix.