Duplex stainless steels (DSSs) are promising materials in many fields due to their excellent corrosion resistance and mechanical properties, which are resulted from their microstructure consisted of a roughly equal amount of austenite and ferrite phases. As a revolutionary production technology, additive manufacturing (AM) has exhibited tremendous advantages for the fabrication of metal parts of complicated or customized geometry. Wire arc additive manufacturing (WAAM), laser metal deposition (LMD) and laser powder bed fusion (L-PBF) have been utilized to fabricate DSSs. However, it is of a great challenge to achieve expected formation quality and microstructure at the same time, considering the complicated layer-upon-layer process. A delicate control of processing conditions is highly required based on the understanding of DSS materials and AM processes. In this work, an overview of the up-to-date research status and future perspectives on the AM of DSSs is presented from extensive viewpoints including materials, processing, microstructure and properties. The microstructure evolution during the AM processes is highlighted in detail, which explains the change of mechanical properties and corrosion resistance, and provides the direction of processing optimization.

双相不锈钢 (DSS) 由于其优异的耐腐蚀性和机械性能而在许多领域成为有前途的材料，这是由于其微观结构由大致等量的奥氏体和铁素体相组成。作为一种革命性的生产技术，增材制造 (AM) 在制造复杂或定制几何形状的金属零件方面表现出巨大的优势。电弧增材制造 (WAAM)、激光金属沉积 (LMD) 和激光粉末床融合 (L-PBF) 已被用于制造 DSS。然而，考虑到复杂的逐层工艺，同时达到预期的地层质量和微观结构是一个巨大的挑战。基于对 DSS 材料和 AM 工艺的理解，非常需要对加工条件进行精细控制。在这项工作中，从材料、加工、微观结构和性能等广泛的角度概述了 DSS 增材制造的最新研究现状和未来前景。详细突出了增材制造过程中的微观结构演变，解释了机械性能和耐腐蚀性能的变化，并提供了加工优化的方向。