Surface contact fatigue failure of a case hardened pinion shaft

An investigation was made to determine the causes of surface contact fatigue failure of a case hardened driver pinion located in the intermediate shaft of a reducer gearbox used in a sugar and alcohol mill. The examination of the component revealed the presence of a cemented layer substantially thicker than that generally specified for pinions devised for this application. This, associated with the massive presence of brittle threadlike carbon-rich cementite phase (Fe3C) in prior austenite grain boundaries of the pinion teeth, favored surface crack nucleation and propagation during cyclic loading, leading to spallation of the contact surface with the counterpart gear, which impaired the system's operation. Poor carburization practice was discovered as the root cause of the mechanical failure, thus demanding the implementation of a new manufacturing route to avoid problems in similar load-bearing rotating components.

Bibliographic Details

Main Authors:	Rossino,Luciana Sgarbi, Castro,Danilo Borges Villarino de, Moreto,Jeferson Aparecido, Ruchert,Cassius Olivio Figueiredo Terra, Spinelli,Dirceu, Tarpani,José Ricardo
Format:	Digital revista
Language:	English
Published:	ABM, ABC, ABPol 2014
Online Access:	http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392014000300001
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