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Dnepropetrovsky Metallurgichesky Institut

Valentin Nikolaevich Danchenko

Ivan N Potapov

Igor Alexandrovich Chekmarev

Vladimir Mikhailovich Bokov

Fedor Terentievich Vinogradov

Evgeny Stepanovich Bondarenko

Vitaly Nikolaevich Cherny

Petr Alexeevich Loskutov

Petr M Finagin

Alexandr A Zayats

Valery Georgievich Balakin

Alexandr Andreevich Shevchenko

Gennady Ivanovich Gulyaev

Vladimir Petrovich Bednyakov

Sergei P Kutsenko

A working mandrel is composed of several similar sections, each having a working surface on the body thereof. The leading end of each section has a socket, while the trailing one has a projecting portion of a similar configuration for jointing the sections during the rolling step. Rolling is effected on the working mandrel assembled in a head-to-tail fashion and after the rolling cycle is terminated the leading section is transferred to the mandrel cooling and lubricating line and then, cooled and suitably lubricated, is positioned in front of the first roll stand, while the other sections remain between the first and the last roll stands. Put into position in front of the multistand mill may be a previously prepared section instead of that transferred to the mandrel cooling and lubricating line.

Working mandrel and method of rolling elongate hollow pieces in a

The invention relates to the manufacture of seamless tubes by the method of tube rolling. According to the method of the present invention a hollow blank is deformed with regard to its wall thickness, the deformation being alternated at least twice with a reduction of the diameter of the blank by means ofa mandrel with alternating groups of grooves for deformation and groups for reduction. The mandrel diameter at the portions corresponding to the groups of reduction grooves is smaller than the mandrel diameter at the preceding portions corresponding to the groups of grooves designed for deformation of the hollow blank to change the wall thickness thereof. During the continuous rolling, this enables subsequent levelling out of bulges at the tube ends in grooves on the mandrel during the deformation of the blank wall. As a result, the range of rolled tubes is considerably enlarged with an increased production of small-diameter thick-walled tubes and large-diameter thin-walled tubes without bulged ends.

Method and rolling mill for continuous tube rolling

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Dnipro, Ukraine

Valentin Nikolaevich Danchenko