Corrosion Behavior of Brazed Zinc-Coated Structured Sheet Metal

Abstract

Arc brazing has, in comparison to arc welding, the advantage of less heat input while joining galvanized sheet metals. The evaporation of zinc is reduced in the areas adjacent to the joint and improved corrosion protection is achieved. In the automotive industry, lightweight design is a key technology against the background of the weight and environment protection. Structured sheet metals have higher stiffness compared to typical automobile sheet metals and therefore they can play an important role in lightweight structures. In the present paper, three arc brazing variants of galvanized structured sheet metals were validated in terms of the corrosion behavior. The standard gas metal arc brazing, the pulsed arc brazing, and the cold metal transfer (CMT®) in combination with a pulsed cycle were investigated. In experimental climate change tests, the influence of the brazing processes on the corrosion behavior of galvanized structured sheet metals was investigated. After that, the corrosion behavior of brazed structured and flat sheet metals was compared. Because of the selected lap joint, the valuation of damage between sheet metals was conducted. The pulsed CMT brazing has been derived from the results as the best brazing method for the joining process of galvanized structured sheet metals.

Effect of Coating Thickness on the Corrosion Behavior of Galvanized Steel in 3.5 % NaCl Solution

“…The color of the product of corrosion was found to be reddish for T1 and whitish for T3. It is known that the white product of corrosion in galvanized steel can be mainly composed of zinc based products of corrosion such as zinc hydroxide, zinc carbonate and zinc oxide in chloride containing aqueous environments [19]. Therefore, from the observed color of the rusts, it could be understood that the amount of Zinc rich product of corrosion is increased as the coating thickness is increased.…”

Fatigue Performance of GMA-Brazed Non-load Carrying Joints Made of Ultra-High-Strength Steel

“…It has been demonstrated that in non-load carrying joints such softening might result in the joint area being the weakest component of a structure [1]. GMAB (or MIG brazing) is a well-known process in industries where thin-walled structures are constructed using galvanized steel plates [2][3][4][5]. By using GMAB instead of conventional fusion welding, the beneficial effect of the galvanized layer, e.g.…”