钢结构在役涂层的配套性和再涂性研究

目的 针对某濒海大型钢结构设施表面涂层大面积粉化、失光、变色现象，研究钢结构在役涂层老化失效后几种面漆重涂的配套性和再涂性。方法 进行面漆重涂试验，完成涂层体系的配套性和再涂性测试，评价在役涂层重涂后的性能。首先，将几种典型的钢结构在役防护涂层体系打磨掉老化的面漆后，作为初始涂层(涂层A)；然后，选取在循环盐雾和氙灯老化加速试验中表现较好的涂层面漆作为涂层B，将涂层B涂敷在涂层A上，制备成新的涂层体系；最后，完成涂层配套性和再涂性测试，分析30组涂层配套组合的附着力、压痕长度、杯突试验结果，提出面漆重涂时的涂层优化配套方案。结果 涂层体系再涂后，所有试验件的涂层拉拔附着力测试均大于5 MPa，30组涂层体系组合中有9组(占30%)再涂涂层压痕长度降低，杯突试验测试值多在1.5~4.5 mm。结论 涂层体系再涂后，满足涂装防护涂层附着力的一般要求，抗压痕性能有所提高，延展性较好。在进行涂层再涂性和配套性评价时，应重点考虑附着力满足使用要求，提高涂层体系涂层的粘结力，其次才是考虑硬度和延展性。

Compatibility and Recoatability of In-service Coatings for Steel Structures

In view of the phenomenon of the surface coating of a large-scale steel structure facility near the sea, such as powder, loss of light and discoloration, the compatibility and repainting ability of several top coatings after the ageing of the in-service coating for steel structure were studied. The finishing paint repainting test was carried out to complete the test of coating system compatibility and repainting performance, and to evaluate the performance of in-service coating after repainting.First, several typical in-service protective coating systems for steel structures are sanded off the aged topcoat as the initial coating (coating A). Then, the top coat B, which performed well in the accelerated test of cyclic salt spray and xenon lamp, was chosen as coating B. A new coating system was prepared by coating B on coating A. Finally, the test of coating compatibility and recoating property is completed, and the test results of adhesion, indentation length and cupping of 30 coating combinations are analyzed. After repainting, the tensile adhesion of all the samples was more than 5 MPa, and the indentation length of re-coating was decreased in 9 of 30 groups (30%) , most of the cupping test values were 1.5~4.5 mm. The coating system can meet the general requirements of coating protective coating adhesion, anti-indentation performance has been improved, the ductility is better after repainting. In the evaluation of coating recoatability and compatibility, the adhesive force should be considered to meet the application requirements, and the adhesive force of the coating system should be improved, and the hardness and ductility should be considered next.