Fatigue behaviour of additively manufactured low alloy steel

Abstract

In recent years, Additive Manufacturing (AM) has witnessed significant growth, offering numerous advantages over traditional manufacturing methods. Its widespread adoption in major industries like medical, aerospace, automotive, and marine offshore highlights its versatility. As the marine offshore sector evolves to meet diverse needs, there is an increasing demand for intricate components. Despite the common use of structural steels like Low Carbon Steel in shipbuilding due to their excellent mechanical properties, current AM methods still face challenges in optimizing the process and reducing defects like porosities, lack of fusion, inclusions, and unmelted feedstock.

This Final Year Project focuses on exploring the microstructure and fatigue behaviour of Low Alloy Steel produced through the Binder Jetting method in 3D printing. The investigation began with a tensile test to determine essential mechanical properties such as ductility, yield, and tensile strengths. Subsequent fatigue tests were carried out with applied stresses corresponding to the respective yield strengths. The resulting fatigue properties were compiled into a table and represented on an S-N curve for comparative analysis among different specimens. The study also includes fractographic analysis using a Scanning Electron Microscope (SEM) to examine various fractured surfaces, identify defects leading to specimen failure, and discuss their impact on fatigue life.