The pierce-and-draw process is particularly well suited for the production of thick-walled, seamless large-diameter tubes. These are used not only for power generation or oil exploration applications, but also as base components for machine-building purposes. Precise control of the whole process yields high-tech products. "When service conditions become really tough, the seamless steel tube is nearly unbeatable", says Wolfgang Grummer, general manager (marketing & sales) of added value products, Vallourec & Mannesmann Tubes GmbH. The meticulous process can be observed in the huge press hall of the V&M factory in Dusseldorf-Reisholz (Germany). A pit furnace cover slides aside and a big dogging crane claws into the glistening heat, lifting out a huge steel block glowing bright red. The crane transfers the ingot to the huge press at the centre of the hall, where it is inserted into a round steel tool which then slides under the press cylinder. Slowly, man-size piercing mandrel comes down until it contacts the surface of the ingot. Bringing to bear a force of 40MN (4,000 tonnes), the press forces the mandrel deeper and deeper into the massive block.
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