RESUMEN
The aim of this paper is to investigate the factors (build orientation, sample conditions, and R-ratio) that affect the cyclic response of laser powder-bed fusion stainless steel 316L and 17-4 PH parts. Initially, the data set was analyzed to confirm the normality assumption. The significant and insignificant factors that affect the fatigue life were identified using analysis of variance (ANOVA). Main effects for different sample conditions were also analyzed. Process and reproducibility assessment were performed to study the effect of process factors. Combining fatigue data sets was recommended as the best approach to accurately predict the fatigue behavior of LPBF 316L and 17-4 PH parts. Finally, the effect of sample conditions on fatigue life was quantified. The highest fatigue life was achieved with Machined-Polished surfaces.
RESUMEN
Friction stir processing (FSP) technology has received reasonable attention in the past two decades to process a wide range of materials such as aluminum, magnesium, titanium, steel, and superalloys. Due to its thermomechanical processing nature, FSP is used to alter grain structure and enhance mechanical and corrosion behavior in a wide range of steels. The refinement in grains and phase transformations achieved in steel after FSP affects hardness, tensile properties, fracture toughness, fatigue crack propagation rate, wear resistance, and corrosion resistance. A number of review papers are available on friction stir welding (FSW) or FSP of nonferrous alloys. In this article, a comprehensive literature review on the FSP/FSW of different types of steels is summarized. Specifically, the influence of friction stir processing parameters such as advancing speed, rotational speed, tool material, etc., on steels' performance is discussed along with assessment methodologies and recommendations.