Adhesion of batch hot-dip galvanized components

Abstract

Structural bonding of batch hot-dip galvanized components poses a particular challenge against the background of the build-up of the zinc coating in the form of different zinc-iron phases. As part of a research project, parameters influencing the zinc coating, the pre-treatment of the zinc substrate, and the adhesive were investigated with regard to the load-bearing capacity of a bonded joint. The variation of the zinc coatings was achieved by using four different steel grades in combination with four batch galvanizing processes. Therefore, small-scale, thick shear tensile specimens were uniformly fabricated, galvanized, bonded in pairs, and mechanically tested. A second series of tests was aimed at the feasibility of an adhesive bond of batch galvanized, medium-scale components under realistic boundary conditions. The test specimens were produced by varying the surface preparation and the adhesive and tested mechanically to shear failure. The results of both test series show that zinc-coated components can be adhesively bonded well and reliably, and, by this, a high load-bearing capacity can be achieved in the bonded joint. The small-scale tests clearly show that the type of zinc coating and its structure obviously have a significant influence on the load-bearing capacity. In summary, it can be stated that the relevant material and process-related influences on the shear load-bearing behavior of bonded joints of batch hot-dip galvanized components were demonstrated by means of the two test series, and the basis for implementing such joints on real load-bearing structures was laid. The presented procedure (small-scale tests and component tests) can be used as a suggestion for a later application in practice.

Abrasive Wear Behavior of Batch Hot-Dip Galvanized Coatings

“…The high resistance of batch hot-dip galvanized coatings under mechanical load with values similar to those found by Katzung et al [11] were also demonstrated by Abeln et al [8] as part of investigations into the behavior of the adhesive joints of batch hot-dip galvanized components. Using thick shear tensile specimens and varying the zinc coating, the load-bearing capacity of the bonded joints under mechanical shear loading-and, thus, indirectly, also of the zinc coatings-was tested.…”

“…In Table 1, an overview of the different phases and their properties is given. Depending on various factors, such as the reactivity of the steel, the dwell time in the zinc bath, or the zinc bath temperature, HDG coatings with a thickness of 50-250 µm are manufactured [7][8][9][10].…”

“…Table 1. Phases of hot-dip galvanized coatings and their properties [8][9][10]. Regarding the behavior of HDG coatings when subjected to mechanical stress, their microstructure and adhesion are of particular importance.…”

Use of adhesives in preloaded bolted connections for hot‐dip galvanised constructions

“…However, this effect is regarded as low in comparison to the load-bearing behaviour of adhesive bondings with various chemical compositions of the zinc baths. In [17], divergences of the shear strength of the adhesive bonding up to 239 % considering various zinc baths with steels in the Sebisty range are verified.…”