高强度低合金钢中纳米析出相对腐蚀行为影响的研究进展

高强度低合金钢中Nb、V和Ti等微合金化元素的纳米析出相对于调控钢的组织和性能具有重要作用，它可以确保钢基体同时拥有较高的力学性能和较强的耐蚀性能。本文基于国内外最新研究现状，系统阐述了纳米析出相在高强度低合金钢中的存在形态以及其对钢中氢扩散、均匀腐蚀、应力腐蚀开裂以及各类氢损伤等腐蚀行为的影响规律和机制。研究表明，纳米析出相对钢基体腐蚀行为的影响受其尺寸、数量和分布状态的控制。细小且与基体共格或半共格的纳米析出相不仅可以通过改善钢的微观组织（包括亚结构）提高耐蚀性能，其导致的不可逆氢陷阱及对氢扩散的强烈抑制作用还可以极大提高抗应力腐蚀和各类氢损伤的能力。而大尺寸的非共格析出相则可能恶化钢基体的耐蚀性能和促进氢损伤。最后展望了目前关注较少的纳米析出相对腐蚀疲劳影响的相关研究。明确纳米析出相对高强度低合金钢腐蚀行为的影响规律与机制将有助于更高品质耐蚀钢的开发和应用。 

Influence of nanosized precipitate on the corrosion behavior of high-strength low-alloy steels:a review

Compared with the widely used plain carbon steels, high-strength low-alloy steels exhibit high tensile strength, excellent fatigue performance, good plasticity, and toughness, and have attracted considerable attention in recent years. In the strengthening and toughening of high-strength low-alloy steels, the addition of carbide-forming and nitride-forming elements (i.e., Nb, V, and Ti) promotes the formation of nanosized precipitates. Nanosized precipitate in high-strength low-alloy steels plays a significant role in the microstructure optimization, which could maintain the high mechanical properties and excellent corrosion resistance of the steel matrix. With the advancement of characterization techniques and simulation methods in the atomic scale over the past few decades, the effect of nanosized precipitate on the corrosion behavior of high-strength low-alloy steels has become increasingly clear. Based on the obtained achievements in China and abroad, the existing morphology of nanosized precipitate and its influence on hydrogen diffusion, uniform corrosion, stress corrosion cracking, and hydrogen-induced damage were reviewed systematically in this study. Results show that the influence of nanosized precipitates on the corrosion behavior of high-strength low-alloy steels depends on its size, quantity, and status of crystal deposition. The fine and (semi-)coherent precipitate in the steel matrix can significantly improve not only the corrosion resistance by refining the microstructure (including the substructure) but also the resistance to hydrogen-induced damage by acting as an irreversible hydrogen-trapping site and strongly restraining hydrogen diffusion. However, incoherent precipitates with a large size would deteriorate the corrosion resistance because of the loss of microstructure optimization. Finally, this study forecasts the influence of nanosized precipitate on fatigue corrosion of high-strength low-alloy steels, which has not been investigated in previous studies. The optimization of the corrosion resistance of high-strength low-alloy steels can be achieved by controlling the nanosized precipitates. Clarifying the influence of nanosized precipitate on corrosion behavior would contribute significantly to the development of high-quality high-strength low-alloy steels.