| Autor: |
Skripalenko MM; Department of Metal Forming, National University of Science and Technology MISiS, Leninski Prospect, 4, 119049 Moscow, Russia., Rogachev SO; Department of Physical Metallurgy and Physics of Strength, National University of Science and Technology MISiS, Leninski Prospect, 4, 119049 Moscow, Russia., Romantsev BA; Department of Metal Forming, National University of Science and Technology MISiS, Leninski Prospect, 4, 119049 Moscow, Russia., Bazhenov VE; Casting Department, National University of Science and Technology MISiS, Leninski Prospect, 4, 119049 Moscow, Russia., Skripalenko MN; Department of Metal Forming, National University of Science and Technology MISiS, Leninski Prospect, 4, 119049 Moscow, Russia., Danilin AV; Department of Metal Forming, National University of Science and Technology MISiS, Leninski Prospect, 4, 119049 Moscow, Russia. |
| Abstrakt: |
AA6060 ingots were pierced in a two-high screw rolling mill (MISIS-130D) with guiding shoes (Mannesmann mill type). Three different plugs, i.e., a conventional entire plug, a plug with a cavity, and a hollow plug, were used for piercing. We established that the grain size decreases after piercing, by order of magnitude, compared to the initial non-pierced annealed bill, with a grain size of 100-400 μm, and the hollow shell grains are elongated along the piercing direction. The produced hollow shells had 30% higher hardness than the initial billet. The highest hardness values were obtained after piercing the conventional entire plug. The most uniform hardness distribution through the hollow shell's volume was obtained after piercing the hollow plug. The cross and longitudinal section hardness measurements demonstrate that the hardness decreases from the outer surface to the inner surface of the hollow shells. |
