FRAME FOR TWO-WHEELER AND ALL-TERRAIN VEHICLE AND PROCESS FOR PRODUCING SAME

摘要

A frame member for use in a two-wheeled vehicle and an all-terrain vehicle that includes a plurality of Al members each made of a 7000 series Al alloy having a high strength is provided in which weld crack sensitivity is reduced and a weld joint having an excellent strength is provided. The alloy composition of the 7000 series Al alloy, which provides the Al member, contains Cu: 0.01 to 0.50%, Mg: 0.5 to 2.1%, and Zn: 4.0 to 8.5%, the balance consisting of Al and inevitable impurities. Further, in the production of the frame member, the plurality of Al members is integrated by welding using a filler metal containing Mg: 5.5 to 8.0%, Cr: 0.05 to 0.25%, Ti: 0.25% or less, Si: 0.4% or less, Fe: 0.4% or less, Cu: 0.1% or less, Zr: 0.05% or less and Zn: 0.25% or less, and the balance consisting of Al and inevitable impurities.