Failure analysis of stellite dies for brass extrusion: The effect of aging

Bourithis, L; Gontzes, V; Papadimitriou, GD

dc.contributor.author	Bourithis, L	en
dc.contributor.author	Gontzes, V	en
dc.contributor.author	Papadimitriou, GD	en
dc.date.accessioned	2014-03-01T01:55:33Z
dc.date.available	2014-03-01T01:55:33Z
dc.date.issued	2006	en
dc.identifier.issn	0924-0136	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/27785
dc.subject	brass	en
dc.subject	extrusion	en
dc.subject	cobalt alloys	en
dc.subject	stellite	en
dc.subject	aging	en
dc.subject	fatigue	en
dc.subject.classification	Engineering, Industrial	en
dc.subject.classification	Engineering, Manufacturing	en
dc.subject.classification	Materials Science, Multidisciplinary	en
dc.subject.other	COBALT-BASE SUPERALLOY	en
dc.subject.other	SECONDARY M6C PRECIPITATION	en
dc.subject.other	ALUMINUM EXTRUSION	en
dc.subject.other	ALLOY	en
dc.subject.other	MICROSTRUCTURE	en
dc.subject.other	BEHAVIOR	en
dc.subject.other	FRACTURE	en
dc.title	Failure analysis of stellite dies for brass extrusion: The effect of aging	en
heal.type	journalArticle	en
heal.language	English	en
heal.publicationDate	2006	en
heal.abstract	Improving the performance of the extrusion tools and predicting their life postulates knowledge of their failure mechanisms. In this work, actual failure cases of brass extrusion dies made from stellite 413 are presented and their mechanisms are studied. It is found that exposed parts of the die suffer from cyclic loading which, in combination with manufacturing defects and design imperfections, promote the initiation of fatigue cracks. Aging during service of stellite 413 inserts reduces die life due to the formation of a network of brittle carbides surrounding the ductile cobalt dendrites. During extrusion, the M7C3 carbide dissolves in the cobalt matrix leading to precipitation of new M23C6 and eta-carbide types. This occurs at relatively low working temperatures, in the range of 600-650 degrees C, instead of 850-1100 degrees C as referred in the resent literature, and is probably assisted by high stresses prevailing during the extrusion process. (c) 2006 Elsevier B.V. All rights reserved.	en
heal.publisher	ELSEVIER SCIENCE SA	en
heal.journalName	JOURNAL OF MATERIALS PROCESSING TECHNOLOGY	en
dc.identifier.isi	ISI:000242919000087	en
dc.identifier.volume	182	en
dc.identifier.issue	1-3	en
dc.identifier.spage	608	en
dc.identifier.epage	614	en