Influence of scanning strategy on printing quality and properties of selective laser melted 18Ni300 maraging steel

In order to study the influence of scanning strategy on the printing quality and properties of the formed parts,unidirectional scanning along one axis (X-scan),unidirectional scanning with 90° rotation in each layer (XY-scan),strip partition scanning strategy with direction changes in each layer (S-scan), checkerboard partition scanning strategy with direction changes in each layer (C-scan) were chosen to print 18Ni300 maraging steel by selective laser melting (SLM) process.The effects of different scanning strategies on the surface morphology, relative density,microstructure and mechanical properties of printed parts were studied systematically. The anisotropy of tensile properties of different scanning strategies in different forming directions was analyzed. The results show that the print quality and properties of the partition scanning strategies are better than that of X scanning strategy and XY scanning strategy. The reason is that during the printing process, the partition scanning strategy can divide each layer of laser scanning into multiple areas for printing, which improves the condensing rate for each layer. Compared with X scanning strategy and XY scanning strategy, the scanning direction of the partition scanning strategy changes periodically, which not only helps to fill the bulge and lap gap of the upper layer, but also reduces the heat accumulation and improves the performance of the sample.