METHOD AND APPARATUS FOR REDUCING AND SIZING HOT ROLLED FERROUS PRODUCTS

• Main Authors: KIEFER, BRUCE, V, SHORE, T., MICHAEL, KEYZER, PIETER, L
• Format: Patent
• Language: English; French
• Published: 14.03.2002
• Edition: 7
• Subjects: MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVINGMATERIAL; PERFORMING OPERATIONS; PUNCHING METAL; ROLLING OF METAL; TRANSPORTING

A method of continuously rolling a ferrous workpiece (10) into a finished round (10e), comprising rolling the workpiece in successive first and second roll passes (P1, P2) at an elevated temperature of between about 650 to 1000 C, the first and second roll passes each being defined by two work rolls (12, 16) and being dimensioned to effect a combined reduction in the cross sectional area of the workpiece of at least about 20-55%, with an accompanying effective strain pattern dominated by a concentration of maximum effective strain at a central region (a) of the cross sectional area; and while the effective strain pattern remains dominated by a concentration of maximum effective strain at a central region of the cross ection, continuing to roll the workpiece in at least third and fourth consecutive roll passes (P3, P4), each of the third and fourth roll passes being defined by at least three rolls (20, 24) and being sized to effect a combined reduction in the cross sectional area of the workpiece of not more than about 4-25 %. A method of continuously rolling a ferrous workpiece into a finished round, comprising rolling the workpiece in successive first and second roll passes at an elevated temperature of between about 650 to 1000 DEG C, the first and second roll passes each being defined by two work rolls and being dimensioned to effect a combined reduction in the cross sectional area of the workpiece of at least about 20-55%, with an accompanying effective strain pattern dominated by a concentration of maximum effective strain at a central region of the cross sectional area; and while the effective strain pattern remains dominated by a concentration of maximum effective strain at a central region of the cross ection, continuing to roll the workpiece in at least third and fourther consecutive roll passes, each of the third and fourth roll passes being defined by at least three rolls and being sized to effect a combined reduction in the cross sectional area of the workpiece of not more than about 4-25 %. Procédé de laminage continu d'une pièce ferreuse afin d'obtenir un arrondi fini, ce qui consiste à laminer la pièce dans une première et une deuxième passe de laminage successives à température élevée entre 650 et 1000 DEG C, cette première et cette deuxième passe de laminage étant définies chacun par deux rouleaux de laminage et dimensionnées afin d'effectuer une réduction combinée dans la zone de section transversale de la pièce d'au moins 20-55 %, avec une configuration de déformation effective associée dominée par une concentration de déformation maximum dans une zone centrale de cette section transversale. Tandis que la configuration de déformation effective est toujours dominée par une concentration de déformation maximum au niveau d'une zone centrale de la section transversale, on continue à laminer la pièce dans au moins une troisième et quatrième passe de laminage consécutives, chacune de cette troisième et quatrième passe de laminage étant définie par au moins trois rouleaux et dimensionnée de façon à effectuer une réduction combinée de la section transversale de la pièce de 4-25 % maximum.