ABSTRACT

Flash butt welding is a resistance welding process that offers great advantages due to its high thermal efficiency, simplicity and high speed, makes it ideal for welding mooring chains. Despite its advantages, numerous corrosion problems are still being found in practice, both in the heat-affected zone and the weld line. Literature is scarce about it, limiting mostly to state the problem. The majority of the studies attribute this preferential corrosion to local changes in the microstructure that induce a galvanic coupling effect.

Mooring chain R3 grade steel with preferential corrosion along the weld line has been studied from both metallographic examinations and electrochemical methods. Small differences were found in the microstructure of the heat-affected zone and base material (mainly composed of tempered martensite) but nevertheless, significant with respect to its corrosion behaviour. The corrosion mechanisms are discussed with particular attention to the electrochemical differences around the welding line.

摘要

闪光对焊是一种电阻焊接工艺，由于其热效率高、操作简单、速度快，因此非常适合焊接系泊链。尽管有其优点，但在实践中仍然发现了许多腐蚀问题，无论是在热影响区还是在熔接线处。关于它的文献很少，主要是为了说明问题。大多数研究将这种优先腐蚀归因于微观结构的局部变化，从而引起电流耦合效应。

已从金相检验和电化学方法研究了沿熔合线优先腐蚀的系泊链 R3 级钢。在热影响区和母材（主要由回火马氏体组成）的微观结构中发现了微小的差异，但在腐蚀行为方面却很显着。讨论了腐蚀机制，特别注意焊接线周围的电化学差异。