Patent ID: 6716390
Filing Date: 2004-04-06
Classification: B21C,C22C

Abstract:
An automotive structural member, such as a side frame, a rear frame, a center pillar, a side sill, and a floor frame, requiring spot weldability, surface treatment property, toughness, and fatigue strength, made from an extruded aluminum alloy, comprising 2.6 to 5 wt % of Si, 0.15 to 0.3 wt % of Mg, 0.3 to 2 wt % of Cu, 0.05 to 1 wt % of Mn, 0.2 to 1.5 wt % of Fe, 0.2 to 2.5 wt % of Zn, 0.005 to 0.1 wt % of Cr, 0.005 to 0.05 wt % of Ti, and 50 to 500 ppm Na, with the balance being made of aluminum and unavoidable impurities, and satisfying the relationship of the following expression (I):(Content of Mn (wt %))+0.32Ã—(content of Fe (wt %))+0.097Ã—(content of Si (wt %))+3.5Ã—(content of Cr (wt%))+2.9Ã—(content of Ti (wt %))&lE;1.36.