In this study, the effects of inter-layer temperature variation on the microstructure, crystallographic orientation, and corrosion performance of a multilayer single-pass wall-shaped 420 stainless steel part fabricated using wire arc additive manufacturing (WAAM) were investigated. The microstructural evolution and texture formation after fabrication were analyzed using scanning electron microscopy (SEM), X-ray diffraction (XRD), and electron backscatter diffraction (EBSD) analysis. The microstructural characterization revealed the formation of a martensitic matrix with delta ferrite and retained austenite as secondary phases as a result of complex thermal history experienced by deposited layers through subsequent reheating and cooling during the fabrication process. The samples deposited at the inter-layer temperature of 200 °C exhibited anisotropic crystallographic behavior, while a relatively isotropic texture was observed for the samples fabricated at the inter-layer temperature of 25 °C. To characterize the electrochemical response of the fabricated samples, open circuit potential (OCP), potentiodynamic polarization (PDP), and electrochemical impedance spectroscopy (EIS) tests were conducted on the prepared samples in naturally aerated 3.5 wt% NaCl electrolyte at ambient temperature. The volume fraction of the retained austenite phase was found to increase by increasing the inter-layer temperature from 25 °C to 200 °C, contributed to the enhanced corrosion performance of the fabricated wall. Localized corrosion attacks were primarily detected adjacent to the delta ferrite phase, regardless of the implemented interlayer temperature during the fabrication process.

在这项研究中，研究了层间温度变化对使用电弧增材制造 (WAAM) 制造的多层单道壁形 420 不锈钢零件的微观结构、晶体取向和腐蚀性能的影响。使用扫描电子显微镜 (SEM)、X 射线衍射 (XRD) 和电子背散射衍射 (EBSD) 分析制造后的微观结构演变和织构形成。微观结构表征表明，由于沉积层在制造过程中通过随后的再加热和冷却经历了复杂的热历史，形成了马氏体基体，其中含有 δ 铁素体和残余奥氏体作为第二相。在 200 °C 的层间温度下沉积的样品表现出各向异性的晶体学行为，而在 25 °C 的层间温度下制造的样品则观察到相对各向同性的织构。为了表征制造样品的电化学响应，在环境温度下在自然充气的 3.5 wt% NaCl 电解质中对制备的样品进行开路电位 (OCP)、动电位极化 (PDP) 和电化学阻抗谱 (EIS) 测试。发现残余奥氏体相的体积分数随着层间温度从 25°C 增加到 200°C 而增加，有助于增强制造壁的腐蚀性能。局部腐蚀攻击主要在δ铁素体相附近检测到，