Skip to Main Content

Abstract

The horizontal cross-travel shaft on a derrick failed after two years of service. The shaft was required to be made of 4140 steel quenched to a hardness of 302 to 352 HRB. The shaft was found to have fractured approximately 13 mm from the change in section between the splined end and the shaft proper. The cracks were found to have propagated in the longitudinal and transverse directions until failures occurred. It was showed by a transverse section through the spline that the longitudinal cracks were initiated at the sharp corners at the roots of the spline teeth. The shaft was subjected to reverse torsional loading by the operation of the derrick and the shaft fatigue fracture was caused by this. The fillets at the roots of the spline teeth were increased in size and polished to minimize stress concentrations in these areas.

You do not currently have access to this chapter.
Don't already have an account? Register

2019. "Fatigue Fracture of a 4140 Steel Cross-Travel Shaft", ASM Failure Analysis Case Histories: Construction, Mining, and Agricultural Equipment

Download citation file:


Close
Close Modal
This Feature Is Available To Subscribers Only

Sign In or Create an Account

Close Modal
Close Modal