On the basis of theory and empirical data, quantitative relationships are formed concerning the formation of porosity and its sources in gas metal arc welding of aluminum. These relationships show that the total amount of hydrogen available to form porosity is a function of individual hydrogen concentrations of the base metal, filler metal, and arc. The amount of hydrogen that can be retained in solution sets the threshold limit for the formation of hydrogen bubbles and, hence, porosity. The source of hydrogen most readily available to reach the solubility limit is the hydrogen of the base metal and filler electrode. The source that can provide hydrogen most readily will be the determining factor. Once this limit is met, the source of hydrogen in the arc will form porosity the volume of which is proportional to the square root of the arc hydrogen partial pressure.
|Original language||English (US)|
|Number of pages||4|
|State||Published - Jan 1 1982|
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