This study investigates the fatigue behaviour of additively manufactured 18Ni300 maraging steel. Specifically, the surface and material parameters impacting fatigue performance are analysed through various post‐treatment combinations. Vertically built miniaturised test samples produced by laser powder bed fusion are tested in as‐built and age‐hardening heat‐treated conditions. To utilise the potential of using additive manufacturing for complex‐shaped parts in which conventional machining tools could have limited access, vibratory finishing and sand blasting are employed. The fatigue results show that in as‐built microstructural condition, both the surface treatments significantly enhanced the fatigue performance, with vibratory finishing outperforming sand blasting owing to better surface finish. After heat treatment, sand‐blasted samples performed better than vibratory‐finished ones because of higher residual stresses. This competing interaction between post‐treatments sheds light on identifying the relative influence of various factors. With systematic postfracture and microstructural analyses highlighting the fatigue influencing factors, recommendations are drawn to select post‐treatments to achieve the desired fatigue performance.

中文翻译：

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激光粉末床熔合制造的18Ni300马氏体时效钢的定制疲劳性能的后处理选择

本研究调查了增材制造的18Ni300马氏体时效钢的疲劳行为。具体而言，通过各种后处理组合来分析影响疲劳性能的表面和材料参数。通过激光粉末床融合生产的垂直建造的小型测试样品在建成和时效硬化的热处理条件下进行测试。为了利用对复杂形状的零件进行增材制造的潜力，在这些形状中，传统的加工工具可能会受到限制，因此采用了振动抛光和喷砂处理。疲劳结果表明，在已建立的微结构条件下，两种表面处理均显着增强了疲劳性能，并且由于具有更好的表面光洁度，振动光洁度优于喷砂处理。热处理后 由于较高的残余应力，喷砂样品的性能优于振动抛光的样品。后处理之间的这种竞争性相互作用为确定各种因素的相对影响提供了启示。通过系统的断裂后和微观结构分析突出疲劳影响因素，建议选择后处理以达到理想的疲劳性能。