硅酸锌车间底漆对船体钢在海水中氢脆行为的影响研究

Effect of Zinc Silicate Workshop Primer on the Hydrogen Embrittlement Behavior of Hull Steel in Seawater

目的 研究硅酸锌车间底漆对船体钢在海水中氢脆行为的影响,为船舶建造涂装工艺提供数据支撑。方法 采用电化学测试、慢应变速率试验(SSRT)、断口微观形貌观察,考察带有硅酸锌车间底漆的船体钢在海水中的氢脆行为。结果 自腐蚀状态下,船体钢及其涂层试样的SSRT断口均以韧性断裂为主,氢脆系数均小于10%,没有明显的氢脆敏感性。–0.94 V阴极保护状态下,船体钢及其涂层试样的SSRT宏观断口均出现了不同程度的撕裂痕,微观断口出现小解理面特征。以硅酸锌涂层做底漆的试样,撕裂痕以及解理面特征最显著,氢脆系数增大最为明显。当船体钢/硅酸锌/环氧耐磨涂层表面出现破损时,氢脆敏感性系数进一步增大。结论 阴极保护状态下,硅酸锌底漆会增加船体钢在海水中的氢脆敏感性。

The work aims to investigate the effect of zinc silicate workshop primer on the hydrogen embrittlement behavior of hull steel in seawater,providing data support for the coating process of shipbuilding.Electrochemical tests,slow strain rate test(SSRT),and microscopic observation of fracture morphology were carried out to examine the corrosion resistance and hy-drogen embrittlement behavior of hull steel in seawater with and without zinc silicate workshop primer.Under self-corrosion conditions,the SSRT fractures of both hull steel and its coated samples were mainly ductile fractures,with hydrogen embrittle-ment coefficients less than 10%,indicating no significant hydrogen embrittlement sensitivity.Under cathodic protection poten-tial of–0.94 V,the SSRT macroscopic fractures of both hull steel and its coated samples exhibited varying degrees of tear marks,and the microscopic fractures showed small cleavage plane features.Among them,the samples with zinc silicate coating as the primer exhibited the most significant tear marks and cleavage plane features,with the most obvious increase in hydrogen embrittlement coefficient.When the surface of the hull steel/zinc silicate/epoxy abrasion-resistant coating was damaged,the hy-drogen embrittlement sensitivity coefficient further increased.Under cathodic protection conditions,the presence of zinc silicate primer can increase the hydrogen embrittlement sensitivity of hull steel in seawater.