Żaba Krzysztof, Szczepańska Martyna, Balcerzak Maciej, Kac Sławomir, Żabinski Piotr
Department of Metal Working and Physical Metallurgy of Non-Ferrous Metals, Faculty of Non-Ferrous Metals, AGH University of Krakow, al. Adama Mickiewicza 30, 30-059 Krakow, Poland.
Faculty of Metals Engineering and Industrial Computer Science, AGH University of Krakow, al. Adama Mickiewicza 30, 30-059 Krakow, Poland.
Materials (Basel). 2025 Sep 1;18(17):4098. doi: 10.3390/ma18174098.
The objective of this study was to investigate the influence of additive manufacturing parameters, specifically using laser powder bed fusion (LPBF), and surface finishing methods on the corrosion rate and behavior of maraging steel M350 components. Samples were fabricated via LPBF employing varying laser powers (80 W, 100 W, and 120 W) and subsequently subjected to mechanical polishing. Corrosion performance was evaluated through 450 h immersion tests in a 3.5% aqueous NaCl solution and potentiodynamic polarization measurements. Microstructural characterization and surface topography assessments were performed using optical microscopy, scanning electron microscopy coupled with energy-dispersive spectroscopy (SEM-EDS), and profilometry. The results demonstrate a strong influence of temperature, manufacturing parameters, and polishing on corrosion processes. At room temperature, higher laser power reduced corrosion rates due to better powder consolidation and lower porosity, whereas at 45 °C, the trend reversed, with the highest corrosion rates observed for samples produced at 120 W. Mechanical polishing significantly reduced surface roughness (Ra from ~7-10 μm to ~0.6-1 μm) but did not improve corrosion resistance; in some cases, it increased corrosion rates, likely due to stress redistribution and exposure of subsurface defects. Potentiodynamic tests confirmed that higher laser power reduced corrosion current density for unpolished surfaces, but polishing increased current density at 80 W more than twofold. The findings indicate that optimizing LPBF process parameters is crucial for improving the corrosion resistance of M350 steel. High laser power (≥120 W) is beneficial at ambient conditions, while lower powers (80-100 W) perform better at elevated temperatures. Mechanical polishing alone is insufficient for enhancing resistance and should be combined with stress-relief and porosity-reduction treatments. These results provide guidelines for tailoring additive manufacturing strategies to ensure reliable performance of M350 steel in chloride-rich environments.
本研究的目的是研究增材制造参数（具体采用激光粉末床熔融（LPBF））和表面处理方法对马氏体时效钢M350部件的腐蚀速率和腐蚀行为的影响。通过LPBF采用不同的激光功率（80瓦、100瓦和120瓦）制造样品，随后进行机械抛光。通过在3.5%的NaCl水溶液中进行450小时浸泡试验和动电位极化测量来评估腐蚀性能。使用光学显微镜、扫描电子显微镜结合能谱仪（SEM-EDS）和轮廓仪进行微观结构表征和表面形貌评估。结果表明温度、制造参数和抛光对腐蚀过程有很大影响。在室温下，较高的激光功率由于更好的粉末固结和更低的孔隙率而降低了腐蚀速率，而在45℃时，趋势相反，120瓦功率下生产的样品腐蚀速率最高。机械抛光显著降低了表面粗糙度（Ra从约7-10μm降至约0.6-1μm），但并未提高耐腐蚀性；在某些情况下，它增加了腐蚀速率，可能是由于应力重新分布和亚表面缺陷的暴露。动电位测试证实，较高的激光功率降低了未抛光表面的腐蚀电流密度，但抛光使80瓦功率下的电流密度增加了两倍多。研究结果表明，优化LPBF工艺参数对于提高M350钢的耐腐蚀性至关重要。高激光功率（≥120瓦）在环境条件下是有益的，而较低功率（80-100瓦）在高温下表现更好。仅机械抛光不足以提高耐腐蚀性，应与应力消除和孔隙率降低处理相结合。这些结果为定制增材制造策略提供了指导方针，以确保M350钢在富氯环境中的可靠性能。
