ABSTRACT

Additive manufacturing (AM) is associated with a sequence of rapid heating and cooling cycles along with large temperature gradients, developing complex thermal histories which have direct influence on resultant microstructures. Such a dynamic and far-from-equilibrium process leads to distinct microstructural features that are expected to cause changes in the corrosion characteristics of AM stainless steels. Currently such changes are not well understood, consequently inconsistencies and disagreements are frequently found in the literature on the corrosion behaviour of AM stainless steels. This paper performs a critical review of corrosion characteristics of AM stainless steels by assessing the effects of their unique microstructural features on corrosion behaviour, with particular focus on new corrosion phenomena and selected critical forms of localised corrosion including pitting corrosion, erosion-corrosion, intergranular corrosion, fatigue corrosion, and stress corrosion cracking. Discussion on the mechanisms of these corrosion phenomena and behaviour, as well as major influencing factors, are undertaken, leading to recommendations and suggestions for future development of AM stainless steels for various corrosive conditions.

摘要

增材制造 (AM) 与一系列快速加热和冷却循环以及大温度梯度相关，会产生复杂的热历史，对所得的微观结构有直接影响。这种动态且远离平衡的过程会导致明显的微观结构特征，预计这些特征会导致增材制造不锈钢的腐蚀特性发生变化。目前这些变化还不是很清楚，因此在关于增材制造不锈钢腐蚀行为的文献中经常发现不一致和分歧。本文通过评估增材制造不锈钢独特的微观结构特征对腐蚀行为的影响，对增材制造不锈钢的腐蚀特性进行了严格审查，特别关注新的腐蚀现象和选定的局部腐蚀的关键形式，包括点蚀、侵蚀腐蚀、晶间腐蚀、疲劳腐蚀和应力腐蚀开裂。对这些腐蚀现象和行为的机制以及主要影响因素进行了讨论，从而为未来在各种腐蚀条件下开发增材制造不锈钢提出了建议和建议。