Abstract：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.
 BREMEN S,MEINERS W,DIATLOV A.Selective laser melting[J].Laser Technik Journal,2012,9(2):33-38.
 JIA Q B,GU D D.Selective laser melting additive manufacturing of Inconel 718 superalloy parts:densification,microstructure and properties[J].Journal of Alloys and Compounds,2014,585:713-721.
 赵宇,宋振明,金剑波,等.激光选区熔化成形Ti-5%TiN复合材料在Hank溶液中的电化学腐蚀性能[J].中国激光,2019,46(9):0902005. ZHAO Y,SONG Z M,JIN J B,et al.Electrochemical corrosion properties of Ti-5%TiN composites formed by selective laser melting in Hank's solution[J].Chinese Journal of Lasers,2019,46(9):0902005.
 杨慧慧,杨晶晶,喻寒琛,等.激光选区熔化成形TC4合金腐蚀行为[J].材料工程,2018,46(8):127-133. YANG H H,YANG J J,YU H C,et al.Corrosion behaviour of selective laser melted TC4 alloy[J].Journal of Materials Engineering,2018,46(8):127-133.
 陈帅,陶凤和,贾长治.选区激光熔化成型18Ni300钢显微组织与性能研究[J].铸造技术,2019,40(7):657-661. CHEN S,TAO F H,JIA C Z.Study on microstructure and properties of 18Ni300 steel fabricated by selective laser melting[J].Foundry Technology,2019,40(7):657-661.
 赖莉,徐震霖,何宜柱.热处理对SLM 18Ni300马氏体时效钢组织及腐蚀性能的影响[J].表面技术,2019,48(12):328-335. LAI L,XU Z L,HE Y Z.Effect of heat treatment on microstructure and corrosion properties of SLM 18Ni300 maraging steel[J].Surface Technology,2019,48(12):328-335.
 臧艳艳.18Ni-300马氏体时效钢选区激光熔化成形组织性能研究[D].重庆:重庆大学,2017. ZANG Y Y.Mechanical and microstructural investigation of 18Ni-300 maraging steel manufactured by selective laser melting[D].Chongqing:Chongqing University,2017.
 KUNZE K,ETTER T,GRASSLIN J,et al.Texture,anisotropy in microstructure and mechanical properties of IN738LC alloy processed by selective laser melting (SLM)[J].Materials Science and Engineering:A,2014,620:213-222.
 WAN H Y,ZHOU Z J,LI C P,et al.Effect of scanning strategy on grain structure and crystallographic texture of Inconel 718 processed by selective laser melting[J].Journal of Materials Science & Technology,2018,34(10):1799-1804.
 SUN S H,HAGIHARA K,NAKANO T.Effect of scanning strategy on texture formation in Ni-25 at.%Mo alloys fabricated by selective laser melting[J].Materials & Design,2018,140:307-316.
 RASHID R,MASOOD S H,RUAN D,et al.Effect of scan strategy on density and metallurgical properties of 17-4PH parts printed by selective laser melting (SLM)[J].Journal of Materials Processing Technology,2017,249:502-511.
 ALMANGOUR B,GRZESIAK D,YANG J M.Scanning strategies for texture and anisotropy tailoring during selective laser melting of TiC/316L stainless steel nanocomposites[J].Journal of Alloys and Compounds,2017,728:424-435.
 LU Y J,WU S Q,GAN Y L,et al.Study on the microstructure,mechanical property and residual stress of SLM Inconel-718 alloy manufactured by differing island scanning strategy[J].Optics and Laser Technology,2015,75:197-206.
 HILLIER S.Accurate quantitative analysis of clay and other minerals in sandstones by XRD:comparison of a Rietveld and a reference intensity ratio (RIR) method and the importance of sample preparation[J].Clay Minerals,2000,35(1):291-302.
 KURZ W,FISHER D J.Fundamentals of solidification[M].Zurich,Switzerland:Trans Tech Publications,1986.