Steels have been applied for many machine structures, and strength and heat resistance of that materials are required more recently. The purpose of this study is evaluating and comparing the fatigue damage of the low alloy steel castings which changed the addition quantity of Vanadium to improve the strength and the resistance or gave heat damage. In this report, tensile fatigue testing was done and fracture characteristics of that materials were researched with AE method. As the results, the effectiveness of Vanadium about the strength of that materials affected by heat was confirmed by Chaos analysis results of AE signals.
