Al-5%Mg合金鋳物の電子ビーム溶接に関する一研究

概要

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In electron beam welding of Al-5%Mg alloy casting (JISH5202,Class 7 AC7A), effects of factors such as welding conditions, base metal thickness (6,16 mm), Ti addition (Ti free, 0.12%Ti) and etc. on welding phenomena, metallurgical and mechanical properties of weld zone have been investigated by microscopic observation, thermal cycle measurement, grain size measurement, fatigue test and etc. The results obtained are as follows : (1) In welding of AC7A with 6 mm thickness, arcing phenomena are reduced by proper welding condition and weld zone with sound mechanical propevties are obtained. In welding AC7A (Ti) with 6 mm thickness, arcing phenomena are prevented by beam current at 5% down of filament current and weld zone with sound mechanical propevties are obtained.(2) In welding of AC7A and AC7A(Ti) with 16 mm thickness, arcing phenomena are prevented by combined conditions such as low power density of beam (a_b ; 1.2), preheating (130℃) by EB passes and beam current at 5% down of filament current and weld zone with sound mechanical properties are obtained.(3) Intercrystalline cracks in HAZ are observed with AC7A, 16 mm thickness welded joints. Eutectic compositions (mainly Al_3Mg_2) with low melting point are recognized in intercrystalline cracks in HAZ.(4) Al-5%Mg alloy casting with 0.12%Ti addition shows good weldability owing to refined grain size of base metal and HAZ.
社団法人溶接学会の論文
1983-11-05