17-4 precipitation-hardened (PH) stainless steel (SS) exhibits high strength and good corrosion resistance via Cu-precipitation hardening. Unlike conventional wrought 17-4PH SS, Cu segregation and ε-Cu precipitates are observed in additively manufactured (AM) 17-4PH SS owing to the repeated rapid cooling after heating, which characterizes the AM process. In this study, solution treatment was conducted under various temperatures (1,000, 1,050, 1,100, and 1,200 °C) and durations (1, 2, 4, and 8 h) to minimize the negative effects of Cu segregation and ε-Cu precipitates on precipitation hardening. The mechanical properties and microstructures of each condition for the Cu precipitation behavior were examined. Although the ε-Cu precipitates did not disappear after solution treatment, the average diameter of the ε-Cu precipitates tended to decrease with increasing solution treatment temperature and duration. Therefore, solution treatment at a temperature of 1,200 °C for 8 h was the best, resulting in improved strength compared to the conventional solution treatment at 1,050 °C. Solution treatment on at least 1,100 °C is effective in AM.

17-4 沉淀硬化（PH）不锈钢（SS）通过铜沉淀硬化表现出高强度和良好的耐腐蚀性。与传统的锻造 17-4PH SS 不同，增材制造 (AM) 17-4PH SS 中由于加热后反复快速冷却而观察到 Cu 偏析和 ε-Cu 沉淀，这是 AM 工艺的特征。在本研究中，固溶处理在不同温度（1,000、1,050、1,100 和 1,200 °C）和持续时间（1、2、4 和 8 小时）下进行，以尽量减少 Cu 偏析和 ε-Cu 沉淀物对沉淀硬化。检查了 Cu 析出行为的每种条件下的机械性能和微观结构。虽然固溶处理后ε-Cu析出物并未消失，随着固溶处理温度和持续时间的增加，ε-Cu析出物的平均直径趋于减小。因此，在1200℃固溶处理8h的温度下效果最好，与传统的1050℃固溶处理相比，强度得到了提高。至少 1,100 °C 的固溶处理在增材制造中是有效的。