AUTOMOBILE CHASSIS MEMBER HAVING EXCELLENT CORROSION RESISTANCE, AND METHOD FOR MANUFACTURING THE SAME

PROBLEM TO BE SOLVED: To provide an automobile chassis member having high strength and excellent corrosion resistance of an arc-welded part.SOLUTION: An automobile chassis member comprises: a junction part where hot-dip Zn-Al-based alloy plated steel sheet members of thickness of 1.0-3.0 mm is arc-welded for each other to apply cationic electrodeposition coating, a surface of a steel sheet having a plating layer before welding is continuously covered with a Zn-Al-based alloy layer to a weld bead toe, and an Fe-Al-based alloy layer is present between the Zn-Al-based alloy layer and a base steel. In a steel sheet surface layer part at distance of 2.0 mm or less from the weld bead toe, the Zn-Al-based alloy layer has average Al concentration of 0.2-22.0 mass%, and the Fe-Al-based alloy layer has average Fe concentration of 70.0 mass% or less. 【課題】アーク溶接部の耐食性に優れた高強度の自動車シャシ部材を提供する。【解決手段】板厚１.０〜３.０ｍｍの溶融Ｚｎ−Ａｌ系合金めっき鋼板部材同士をアーク溶接してカチオン電着塗装を施した接合部を持ち、溶接前にめっき層を有していた鋼板表面は溶接ビード止端部まで連続的にＺｎ−Ａｌ系合金層で覆われており、そのＺｎ−Ａｌ系合金層と鋼素地の間にはＦｅ−Ａｌ系合金層が存在し、溶接ビード止端部からの距離が２.０ｍｍ以内の鋼板表層部において、Ｚｎ−Ａｌ系合金層は平均Ａｌ濃度：０.２〜２２.０質量％、且つＦｅ−Ａｌ系合金層は平均Ｆｅ濃度：７０.０質量％以下である自動車シャシ部材。【選択図】図５