Experimental and statistical investigation of fatigue behavior on en 8 steel 080m40 aisi 1040 under heat treatment and shot peening processes

Abstract

When a metal or alloy is subjected to repetitive or cyclic loading, the material experiences fatigue stress. Hence, it becomes imperative to find the fatigue strength of the material to work within endurance limit and avoid early failure. Thus fatigue strength of a material is considered as an important mechanical property to its extended service life. Therefore, fatigue strength enhancement of materials becomes inevitable under cyclic loading condition. The fatigue life of a component is evaluated by the capability of accepting maximum number of loading cycles without failure. This phenomenon depends on factors like applied stress level, stress state, metallurgical state of material and environmental conditions. In particular, rotary elements have shown higher fatigue-failure tendency as compared to other elements. Small changes done on test specimen or experimental condition can produce significant effect on the fatigue behavior of a material. Determination of the fatigue life of the materials that are commonly used for making components like machine parts is significant as they undergo cyclic stresses continuously during their operating life. The EN-8 (AISI 1040) steel has been widely used in the production of power transmission shafts, gears and automobile crankshafts due to its unique metal properties and versatility. Fatigue stresses which are small in magnitude progresses gradually and causes sudden failure. Hence, the operating parts may fail during cyclic loading which may result in manufacturing loss and a delay in production time. Sometimes, fatigue failure of mechanical components may lead to severe damage in machineries as well as to human beings. Different varieties of steels are commonly used in various fields for making structural elements and operating parts. newline