PURPOSE: To obtain a wheel material having a welded joint excellent in mechanical properties and bendability by rounding a strip of an Al-Mg-Si alloy material with a specific composition into a cylindrical shape and then joining its end face by means of DC butt seam welding under specific conditions.
CONSTITUTION: A strip of an Al-Mg-Si alloy which has a composition containing, as essential components, 0.2-1.4%, by weight, Mg, 0.3-1.7% Si, and 0.1-0.8% Cu, also containing at least one or more kinds among 0.05-0.8% Mn, 0.05-0.3% Cr, 0.05-0.3% Zr, and 0.005-0.5% Ti, and having the balance Al with inevitable impurities is prepared. This strip is formed into a cylindrical shape, and its end face is subjected to DC butt seam welding under the following conditions: a combination of welding current density and squeeze pressure takes a value in the range enclosed with lines connecting the points A, B, C, D shown in the figure; weld time is regulated to 10-120 cycles; upset pressure is regulated to a value obtained by adding 0-150N/mm2 to the squeeze pressure.
SASABE SEIJI
HIRANO MASAKAZU
