The Stress Controlled Cyclic Fatigue and Fracture Behavior of Alloy Steel 300M

Abstract

In this manuscript the results of a study aimed at understanding the extrinsic influence of test specimen orientation, with respect to wrought alloy steel plate, on high cycle fatigue properties and fracture behavior is highlighted. The alloy steel chosen was 300 M. Samples of this alloy steel prepared from both the longitudinal and transverse orientation were cyclically deformed over a range of maximum stress and the corresponding number of cycles to failure (NF) was recorded. The influence of test specimen orientation and intrinsic microstructural effects on cyclic fatigue life is presented. At the chosen test temperature, the macroscopic fracture mode was essentially identical regardless of the orientation of the test specimen with respect to the wrought plate. The microscopic mechanisms governing cyclic deformation, fatigue life and final fracture behavior is presented in light of the mutually interactive influences of magnitude of applied stress, intrinsic microstructural effects, orientation of test specimen, and deformation characteristics of the constituents in the microstructure of this alloy steel.