Investigating and Understanding the Cyclic Fatigue, Deformation, and Fracture Behavior of a Novel High Strength Alloy Steel: Influence of Orientation

In this paper, the results of a recent study aimed at understanding the influence of orientation on high cycle fatigue properties and final fracture behavior of alloy steel Pyrowear 53 is presented and discussed. This alloy steel has noticeably improved strength, ductility, and toughness properties compared to other competing high strength alloy steels having a near similar chemical composition and processing history. Test specimens of this alloy steel were precision machined and conformed to the specifications detailed in the ASTM standards for tension testing and stress‐controlled cyclic fatigue tests. Test specimens were prepared from both the longitudinal and transverse orientations of the as‐provided alloy steel bar stock. The machined test specimens were deformed in cyclic fatigue over a range of maximum stress and under conditions of fully reversed loading, i.e., at a load ratio of −1, and the number of cycles‐to‐failure recorded. The specific influence of orientation on cyclic fatigue life of this alloy steel is presented. The fatigue fracture surfaces were examined in a scanning electron microscope to establish the macroscopic fracture mode and to characterize the intrinsic features on the fatigue fracture surfaces. The conjoint influence of microstructure, orientation, nature of loading, and maximum stress on cyclic fatigue life is discussed.

[1]  D. P. Davies,et al.  Influence of stress and environment on the fatigue strength and failure characteristics of case carburised low alloy steels for aerospace applications , 2012 .

[2]  Dierk Raabe,et al.  Overview of processing, microstructure and mechanical properties of ultrafine grained bcc steels , 2006 .

[3]  Y. Furuya,et al.  Inclusion-controlled fatigue properties of 1800 MPA-class spring steels , 2004 .

[4]  Y. Furuya,et al.  Gigacycle fatigue properties of a modified-ausformed Si-Mn steel and effects of microstructure , 2004 .

[5]  Y. Furuya,et al.  Gigacycle fatigue properties of 1800 MPa class spring steels , 2004 .

[6]  I Marines,et al.  Ultrasonic fatigue tests on bearing steel AISI-SAE 52100 at frequency of 20 and 30 kHz , 2003 .

[7]  Y. Furuya,et al.  1010-cycle fatigue properties of 1800 MPa-class JIS-SUP7 spring steel , 2003 .

[8]  H. Ko,et al.  Effects of humidity on crack initiation mechanism and associated S-N characteristics in very high strength steels , 2003 .

[9]  Claude Bathias,et al.  Effect of inclusion on subsurface crack initiation and gigacycle fatigue strength , 2002 .

[10]  Yukitaka Murakami,et al.  Mechanism of fatigue failure in ultralong life regime , 2002 .

[11]  Koji Yamaguchi,et al.  Gigacycle fatigue properties for high-strength low-alloy steel at 100 Hz, 600 Hz, and 20 kHz , 2002 .

[12]  Yukitaka Murakami,et al.  On the mechanism of fatigue failure in the superlong life regime (N>107 cycles). Part 1: influence of hydrogen trapped by inclusions , 2000 .

[13]  M. Larsson,et al.  Effect of inclusions on fatigue behaviour of hardened spring steel , 1993 .

[14]  M. Larsson,et al.  The effect of stress amplitude on the cause of fatigue crack initiation in a spring steel , 1993 .

[15]  Takeshi Naito,et al.  Fatigue behavior of carburized steel with internal oxides and nonmartensitic microstructure near the surface , 1984 .

[16]  A. Götte,et al.  Metall , 1897 .