Paper Title:
Galvanic Weld Metal-Base Metal Corrosion in AZ31 Magnesium Weldments

Arc welds were made on wrought AZ31 magnesium plate using a variable polarity gas-tungsten arc process with AZ61 filler wire. The aluminum content of the weld metal was systematically varied using inserts pre-placed in the weld joint, machined from magnesium die-cast alloys AM20, AM50, AM60, and AZ91. When immersed in 3.5% NaCl + Mg(OH)2 solution at room temperature, pitting corrosion was found to initiate in the weld heat affected zone, spread briefly to the weld metal, and then concentrate in the base metal. Galvanic couples were examined between wrought AZ31 and die-cast alloys to further examine galvanic behavior between wrought and cast materials. Results showed that the cast material was anodic relative to the wrought material over long periods of time, unlike what was observed for weldments. Details of this study will be presented and results will be related to alloy aluminum content and the ability to passivate.

Edited by
Amir Eliezer
C. E. Cross, P. Xu, D. Eliezer, G. Ben-Hamu, "Galvanic Weld Metal-Base Metal Corrosion in AZ31 Magnesium Weldments", Advanced Materials Research, Vol. 95, pp. 39-42, 2010
Online since
January 2010
Authors: Naoya Masahashi, M. Oku, Sadao Watanabe, Shuji Hanada
Abstract:The laminated composite of Fe–Al alloy and CrMo steel was fabricated by clad rolling to provide additional properties to the steel such as...
Authors: T. Monetta, M. Montuori, Antonio Squillace, Francesco Bellucci
Abstract:The current research has assessed the correlation between welding parameters and corrosion behaviour for friction stir welded 6056 aluminium...
Authors: Su Qiu Jia, Guo Jun Liu, Qi Shuang Chen
Abstract:Mg-7.3Al magnesium alloys were investigated in the paper. The paper presents microstructural characterization of Mg-7.3Al alloy after casting...
Authors: Bing Ying Wang, Zhen Tong Sun
Abstract:Four different metal coatings of pure aluminum, aluminum zinc alloy, titanium, aluminum Titanium were prepared on the surface of X80 pipeline...
Authors: Feng Jun Lang, Ying Ma, Jian Rong Liu, Xian Qiu Huang, Mou Cheng Li
Chapter 1: Surface Engineering/Coatings
Abstract:The influence of passivation on pitting corrosion of 316L stainless steel in concentrated seawater was investigated by using cyclic anodic...