| 摘要 |
PROBLEM TO BE SOLVED: To provide a metallic tube having excellent lubrication characteristic for hydroforming, and to provide a hydroforming method. SOLUTION: A lubricant layer whose coefficient of frictionμof inclination is <=0.07 in the sliding test under the high bearing pressure is provided, whereμ=ΔF/(2×ΔP),ΔF is the drawing tension increment when a test piece 2 passes through a bead part 10, andΔP is the load increment in the bead forming direction. The lubricant layer is preferably formed of a solid lubricant consisting of a polymer synthetic wax and an aqueous resin. The lubricant layer is formed, and hydroformed. The metallic tube 1 of the same material can be formed of high forming degree without generating breakage or buckling, the degree of reduction in wall thickness of a formed part is small, and generation of abrasion or gnaw flaws on the surface can be suppressed.
|
