船用低温钢焊接材料的研发与腐蚀方法评价

Research and Development of Welding Materials For Low-temperature Steel and Corrosion Evaluation Methods

海洋工程焊接结构件的腐蚀性能对海洋工程的安全性影响巨大,但目前缺乏科学和系统的评价方法。基于此,本文采用了两种焊接结构件,其焊料合金成分不同,将其浸泡于含腐蚀性细菌的人造海水中,并对其进行腐蚀性能评价。研究表明宏观测试方法(如电化学阻抗法,失重法等)与微观测试方法(微区电化学扫描)所得到的结果并不完全一致。因此,在评价焊接结构件耐腐蚀性时,不能仅通过传统的电化学或失重等测试方法,还应使用微观电化学测试手段。根据焊接结构件的微观腐蚀性能,更佳准确的指导焊接结构件母材与焊材的搭配与选择,提高其整体耐海水腐蚀性能。

The corrosion performance of marine engineering welded structures is of significance for the offshore engineerings safety,however,for that there is hardly any scientific and systematic evaluation methods.Herein,two kinds of welded structures are designed and made with two solder alloys of different composition.Then the corrosion performance of the two coupons were comparatively evaluated by immersion in an artificial seawater containing corrosive bacteria.It is surprisingly found that macroscopic testing results(such as electrochemical impedance,massless testing,etc.)and microscopic testing results(micro-area electrochemical scanning)did not exactly match each other.Therefore,it is not rigorous to evaluate the corrosion resistance of welded structural parts only via the conventional electrochemical method or massless testing,but the microscopic electrochemical testing method should also be applied.Combined with the macroscopic and microscopic corrosion tests,we can be more accurately matching and selecting the base metal and solder of the welded structure,which will guide us to improve its overall seawater corrosion resistance.