STEEL PIPE FOR HYDROFORMING AND HYDROFORMING PROCESS

摘要

PPROBLEM TO BE SOLVED: To provide a steel pipe for hydroforming with which hydroforming having the high amount of bulging is performable without generating wrinkles and cracks by comparatively simple operation. PSOLUTION: This pipe is a steel pipe 1 for hydroforming in which two kinds of steel 10, 11 which are different in strength expressed by (thicknesstensile strength) are arranged so as to be continued in the axial direction of a pipe and the total area of the steel 10 of high strength is smaller than the total area of the steel 11 of low strength. By performing hydroforming by using this steel pipe 1 for hydroforming, the forming having the high amount of bulging is made performable without generating the wrinkles and the cracks. Then, when manufacturing a T-shaped branch pipe, for example, a branch pipe having such the formed height as 2D(mm) to the diameter D(mm) of the steel pipe is easily formed. PCOPYRIGHT: (C)2008,JPO&INPIT