Value stream process for roll forming and bobbin tool friction stir welding aluminum sheet to form vehicle structural rails

A method of manufacturing a plurality of vehicle structural rails, the method comprising:

• uncoiling a coil of aluminum alloy sheet, wherein the aluminum alloy sheet is a 6xxx series aluminum alloy;
• feeding the aluminum alloy sheet into a continuous surface pre-treatment system and forming a pre-treated sheet;
• feeding the pre-treated sheet into a forming lubrication system and applying lubrication to the pre-treated sheet and forming a pre-treated lubricated sheet;
• feeding the pre-treated lubricated sheet into a roll forming machine and forming a tubular shape with a seam;
• bobbin tool-friction stir welding (BT-FSW) the seam of the tubular shape and forming a welded tubular shape with a welded seam;
• cutting the welded tubular shape into a plurality of tubular sections;
• tube bending each of the plurality of tubular sections and forming a plurality of bent tubular sections;
• locally induction heat treating the plurality of bent tubular sections and forming a plurality of recovered bent tubes;
• pre-forming each of the plurality of recovered bent tubes and forming a plurality of pre-formed tubular sections;
• locally induction heat treating each of the plurality of pre-formed tubular sections and forming a plurality of recovered pre-formed tubular sections;
• hydroforming each of the plurality of recovered pre-formed tubular sections and forming a plurality of structural rails;
• and
• trimming the plurality of structural rails and forming a plurality of trimmed structural rails.

A method of manufacturing a plurality of vehicle structural rails, the method comprising:

• uncoiling a coil of aluminum alloy sheet, wherein the aluminum alloy sheet is a 7xxx series aluminum alloy;
• feeding the aluminum alloy sheet into a continuous surface pre-treatment system and forming a pre-treated sheet;
• feeding the pre-treated sheet into a forming lubrication system and applying lubrication to the pre-treated sheet and forming a pre-treated lubricated sheet;
• feeding the pre-treated lubricated sheet into a roll forming machine and forming a tubular shape with a seam;
• bobbin tool-friction stir welding (BT-FSW) the seam of the tubular shape and forming a welded tubular shape with a welded seam;
• cutting the welded tubular shape into a plurality of tubular sections;
• tube bending each of the plurality of tubular sections and forming a plurality of bent tubular sections;
• locally induction heat treating the plurality of bent tubular sections forming a plurality of recovered bent tubes;
• pre-forming each of the plurality of recovered bent tubes and forming a plurality of pre-formed tubular sections;
• locally induction heat treating each of the plurality of pre-formed tubular sections and forming a plurality of recovered pre-formed tubular sections;
• hydroforming each of the plurality of recovered pre-formed tubular sections and forming a plurality of structural rails;
• and
• trimming the plurality of structural rails and forming a plurality of trimmed structural rails.