PURPOSE: To prevent the generation of seizure and scuff marks on the inside surface of a rolled pipe in the stage of rolling a pipe material with a pilger mill by rolling said material within such a working mode range in which the rate of elastic recovery in the stage of releasing the load from the bore of the pipe material in the working region is larger than a specific rate.
CONSTITUTION: A thin-walled pipe material such as a zircalloy pipe, SUS pipe, Ti pipe or the like is subjected to such rolling which satisfies the working mode expressed by the equation [ I ] as the critical condition for generation of seizure obtd. from experiment and calculation so that the rate of elastic recovery when the load in the bore of the pipe material is released in the working region is larger than 0.03mm in the stage of rolling and producing said pipe material with a cold pilger mill. The pipe material having high dimensional accuracy is obtd. without generation of seizure and scuff marks on the inside surface of the thin- walled pipe material in the stage of rolling.
KADOMA TSUTOMU
FUJITA KAZUKI
