Change of Fatigue Properties of Steel-S460NL Damaged by Various Levels of Corrosion

This study investigates the effect of corrosion on the fatigue performance of S460 NL high-strength steel, which is commonly used in offshore structures exposed to harsh conditions. We conducted fatigue tests and analyzed S-N curves over various exposure periods while simulating corrosion conditions in a laboratory setting. The findings show a direct correlation between prolonged corrosion exposure and increased fatigue damage.

Our findings show that longer corrosion periods result in significant accumulation of corrosion products, thereby increasing the severity of metallic corrosion. Using damage theory, we quantified mechanical property degradation, providing important insights into fracture formation mechanisms. High stress levels were associated with fewer fatigue striations and more cumulative damage.

These findings have significant implications for improving the durability and reliability of S460 NL steel in practical engineering applications.

本研究针对常用于极端工况近海工程结构的S460 NL高强度钢，探究腐蚀对其疲劳性能的影响。本研究通过实验室模拟腐蚀环境，开展了不同腐蚀暴露时长下的疲劳试验，并对S-N曲线进行了分析。研究结果表明，腐蚀暴露时长与疲劳损伤程度呈直接正相关关系。

本研究结果显示，更长的腐蚀暴露时长会导致腐蚀产物大量沉积，进而加剧金属腐蚀程度。本研究借助损伤理论对力学性能退化程度进行了量化分析，为断裂形成机制提供了重要的理论参考。此外，高应力水平对应更少的疲劳辉纹（fatigue striations），而累积损伤程度更高。

本研究成果对于提升S460 NL高强度钢在实际工程应用中的耐久性与可靠性具有重要指导意义。