| 摘要 |
PROBLEM TO BE SOLVED: To prevent the inner face of a tube to be rolled from generating a crack by making a Q value and T. Red a specific value so that tensile stress generated at a Pilger rolling time is crossed to metal fibers by using a base tube is which the metal fibers have an angle for the tube axial direction. SOLUTION: A stock billet 1 is heated to a prescribed temp., is pierced and rolled by a piercer roll 2 and is made to a hollow base tube 3 in which metal fibers have an angle for the tube axial directionn. The rolling is conducted under a Q value of >=0.4 and T.Red of <=80% while satisfying the absolute value of the Q value=thickness working rate/outer shape working rate=1n(t1 /t0 )/1n(dm1 /dm0 ) and the formula of the T.Red=area reduction rate (%)=(1-dm1×t1 /dm0×t0 )×100, wherein t0 =base tube thickness, t1 =product thickness, d0 =base tube outer diameter, dm0 =d0 -t0 and dm1 =d1 -t1 .
|
