Study of Multilayer Welded Structure Made of AISI 316LSi Using WAAM

Abstract

The current era makes a pressure on more ecological and economical production, therefore technological innovations are required. Current trend is to use additive manufacturing, which saves production time and reduces the amount of waste. That also contributes to better utilization of raw materials. This paper deals with the analysis of multilayer weld made of AISI 316LSi using WAAM. The aim was to evaluate the integrity of this component via structural analysis. A pipe was welded up and the cross-section of the pipe was analysed using optical microscopy and scanning electron microscopy. The microstructure of the weld metal revealed a dendritic morphology. The dendrites were formed by austenite and the interdendritic space contained δ-ferrite. The boundaries of individual weld layers were sharp and without the presence of an annealed area. SEM-EDS analysis was used in order to obtain maps of the elements distribution in examined microstructure. Globular particles were observed in the microstructure. These particles were identified as oxides rich in silicon and manganese. The mechanical properties were evaluated using microhardness measurement in vertical line and three horizontal lines of the wall. It was found that the microhardness values in the top and middle part of the wall are higher on the inside of the component due to cooling conditions.

Keywords

• AISI 316LSi
• EDS
• microstructure
• MIG
• SEM
• WAAM 1 INTRODUCTION