Slip factor of high strength steel with inorganic zinc-rich coating

• Published in: Thin-walled structures 2020-03, Vol.148, p.106595, Article 106595
• Main Authors: Wang, Yan-Bo, Wang, Yuan-Zuo, Chen, Kun, Jin, Hua-Jian
• Format: Article
• Language: English
• Subjects: Creep test; High strength steel; Inorganic zinc-rich coating; Slip factor; Surface treatment
• ISSN: 0263-8231; 1879-3223
• DOI: 10.1016/j.tws.2019.106595

The loading resistance of slip critical steel connection is determined by the slip factor between faying surfaces and pretension force in bolts. The shot-blasting treatment is a commonly used and simple type of surface treatments. In order to avoid the risk of rusting of shot-blasted surfaces which threatens the structure safety, shot-blasted surfaces are generally coated with aluminum or zinc-based product. In this study, the slip factors of high strength steels (Q550, Q690 and Q890) with inorganic zinc-rich coating are investigated. Two values of coating thickness (60 μm and 80μm) are selected and the influence of thickness of coating on slip factor is studied. Based on classical friction mechanism theory, compared with slip factor of shot-blasted surface, the decreasing of slip factor of surface with inorganic zinc-rich coating is analyzed. Moreover, the coating thickness effect on slip factor is also investigated. Because the difference between the measured slip displacement at 5 min (short-term tests) and 3 h (long-term tests) exceed 2 μm, corresponding creep tests are carried out to evaluate long-term effects. Based on tests results, the recommended values of slip factor of high strength steel surface with inorganic zinc-rich coating is 0.30. •Slip factors of HSSs with inorganic zinc-rich coating are tested.•Steel strength effect on slip factor of steel surface with coating can be ignored.•Creep tests are carried out to study the long-term effect on slip resistance.•Suggested slip factors of HSS surface with inorganic zinc-rich coating are given.