Archives du mot-clef cas concrets

Fracture of a dental prosthesis from an inner thermal crack

Publié le par
Répondre

A new paper about « Case study in Engineering Failure Analysis » published on ScienceDirect.com.

This paper describes the fractographic analysis of a veneer-ZrO2 single-unit dental prosthesis that fractured in a shell-like manner. Analysis of the retrieved fragment revealed that the crack originated in the bulk of the veneer from a thermal flaw located between two layers of the veneering material. Using the measured flaw plane it showed that the conditions of loading at fracture were complex and probably involved important tangential components.

Acceder article

Failure analysis of a burner ring made of 20Cr32Ni1Nb alloy in gas turbine combustion chamber

Publié le par
Répondre

A new paper in « Case study in Engineering Failure Analysis » published on ScienceDirect.com.

The failure analysis of an insert ring of a burner in a 156 MW gas turbine, made of 20Cr32Ni1Nb alloy is presented. Normally, the useful service life of these parts under ideal conditions is about 30000 hours. However, more likely fracture and failure could be observed in5000-hour inspections, which resulted in the early and premature replacement of these parts. This paper brings out the detail of investigation carried out.

Acceder article

Failure cause analysis of deaerator/sourgas stripper cylinder

Publié le par
Répondre

A interesting paper in « Case study in Engineering Failure Analysis » published on ScienceDirect.com.

Circular penetrable cracks occurred at the converge region of upward acid media (H2S and HCOOH) in the opposite position of traverse vapor ingress pipe of the lower part of the upper sealing head of the deaerator/sourgas stripper during the operation of the deaerator/sourgas stripper of the ammonia unit in a chemical fertilizer plant.

Acceder article

Reduction in diversion due to coil break

Publié le par
Répondre

A new case study, in « Case Studies, in Engeeniring Failure Analysis », Volume 2, Issue 2, October 2014, Pages 76–83.

Diversion due to coil break in cold rolled non oriented (CRNO) grades of coils showed an increasing trend during Jan–May’12 at Silicon Steel Mill (SSM), Rourkela Steel Plant (RSP). Coil break increased from a level of less than 1% during to a level of 30% in May’12. Further studies were carried out in the processing lines and material flow was tracked from steel making to final product. The probable reasons were identified and corrective measures were taken leading to reduction in diversion due to coil break less than 2%.

 Acceder article

Crack of a first stage blade in a steam turbine

Publié le par
Répondre

A new Case Study in « Case Studies in Engineering Failure Analysis », Volume 2, Issue 2, October 2014, Pages 54–60

The failure of the first stage blade in a steam turbine of 55 MW was investigated. The blade was made of 17-4 PH stainless steel and has been used for 12 years before failure. The current work aims to find out the main cause of the first stage blade failure. The result showed that the crack at the blade root tang was due to corrosion fatigue and the crack occurred at the blade root fillet owing to stress corrosion cracking.

Acceder article

 

Comprendre et anticiper les défaillances de pièces mécaniques métalliques

Publié le par
Répondre

Le Cetim est leader français en analyse de défaillances mécaniques, enrichi de son expérience de 40 ans, de 1000 nouveaux cas traités par an dans tous les domaines de la mécanique. En confiant votre expertise au Cetim, centre technique indépendant et neutre, vous êtes assuré d’une approche objective, compétente et factuelle.

Ses équipes dédiées pratiquent l’analyse des défaillance au quotidien et s’engagent sur des diagnostics.

telecharger le doc

Recommandations peinture pour armoires électriques

Publié le par
Répondre

La corrosion des armoires électriques d’Alstom Power avait-elle pour origine un problème de peinture ou une raison exogène ? Avec l’aide du Cetim, l’industriel a trouvé la réponse, renforcé ses forces d’investigation et fourni des recommandations.

Pour en savoir plus, lire le document joint.

telecharger le doc

 

Rupture de l’arbre de transmission du rotor de queue

Publié le par
Répondre

Le 2 juillet 2007, un hélicoptère Bell 214B1 effectue des opérations d’hélidébardage depuis Ramsay Arm (C.-B.). L’hélicoptère descend à la verticale et heurte plusieurs arbres avant de se poser brutalement sur le relief accidenté. L’hélicoptère est lourdement endommagé à l’atterrissage, mais il n’y a pas d’incendie. L’enquête révélera une faiblesse structurale de la poutre de queue.

Acceder article

Failure study of a railway rail

Publié le par
Répondre

A interesting paper in « Case study in Engineering Failure Analysis » published on ScienceDirect.com.

In this case study, a failed railway rail which was used for heavy cargo trains was investigated in order to find out its root cause.

This paper brings out the detail of investigation carried out. 

touche Read more