ABSTRACT

Depth-sensing indentation (DSI) technique has been regarded as a power tool for the mechanical measure of small-volume materials or engineering surfaces. Much recent researchalso led to the development of numerous analytical methods for estimating the basic mechanical properties such as Young’s modulus, yield stress, strain hardening exponent, etc. from the indentation load-displacement data. Among these analytical methods, an analytical algorithm proposed by Dao et al (Dao et al. 2001) has been regarded as the representative one due to its more accordant estimations with the measured mechanical properties (Ye et al. 2011, 2012). Since DSI has various merits in practical applications, such as less destructive, quick to perform, and only a relatively small piece of material is required in testing, it provides a promising method for determining the local mechanical properties of welded joints. This is the motive of the present research work to apply the depth-sensing indentation tests and combine with Dao et al’s analytical algorithm to study the local mechanical properties of 304L SS welded joints subjected to low-cycle fatigue (LCF) loadings so as to develop a local mechanical properties-based approach for the fatigue strength analysis of welded components under alternative service conditions.