Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21B—ROLLING OF METAL
  • B21B23/00—Tube-rolling not restricted to methods provided for in only one of groups B21B17/00, B21B19/00, B21B21/00, e.g. combined processes planetary tube rolling, auxiliary arrangements, e.g. lubricating, special tube blanks, continuous casting combined with tube rolling
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21B—ROLLING OF METAL
  • B21B19/00—Tube-rolling by rollers arranged outside the work and having their axes not perpendicular to the axis of the work
  • B21B19/02—Tube-rolling by rollers arranged outside the work and having their axes not perpendicular to the axis of the work the axes of the rollers being arranged essentially diagonally to the axis of the work, e.g. "cross" tube-rolling ; Diescher mills, Stiefel disc piercers or Stiefel rotary piercers
  • B21B19/06—Rolling hollow basic material, e.g. Assel mills
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T29/00—Metal working
  • Y10T29/49—Method of mechanical manufacture
  • Y10T29/4998—Combined manufacture including applying or shaping of fluent material
  • Y10T29/49988—Metal casting
  • Y10T29/49991—Combined with rolling

Definitions

• ABSTRACT Continuously cast, hollow ingots are rolled in a rolling mill of the skew rolling type, whereby the ingot is prevented from turning on its longitudinal axis, and the rolls roll on the ingot.
• the present invention relates to a method of rolling, for stretching or draw rolling a hollow ingot made by continuous casting and cut from the casting.
• Hollow ingots of this type have unusual dimensions, and their particular grain structure poses problems for further shaping.
• conventional rolling techniques for manufacturing of seamless tubing from continuously cast, hollow stock cannot be employed.
• the rolling process and method in accordance with the preferred embodiment of the invention considers particularly these unusual dimensions and grain structure. It is suggested to stretch a hollow, continuously cast ingot by means of hot rolling, using at least three rolls that work in a common plane and have axes that are not at right angles to the direction of rolling. During rolling for stretching, the hollow ingot is restrained to prevent its turning and rotation about the longitudinal axis of the ingot, and the rolls roll on the hollow in" t. A particular tool, such as a mandrel, may be inserted in the ingot for cooperation with the rolls.
• the rather heavy hollow ingot rests essentially motionless during stretching.
• an ingot usually turns about its axis and may impact rather forcefully upon guiding structure and transport rolls. If the ingot is restrained, equipment of the mill is protected. Moreover, fissures and rupture of the material are avoided; it must be observed that the rather coarse, spiky grain structure of a continuously cast product is particularly amenable to rupture at the onset of stretch forming.
• the invention is particularly important for making tubes from hollow ingots of rather large weight.
• the tubes that can be made by the inventive method have actually length that is not obtainable by means of pierce rolling, extrusion molding or by driving a mandrel into a solid ingot.
• a mandrel is also used and inserted in the ingot, and it is essential to prevent turning of the ingot during rolling, e.g. on the mandrel.
• the hollow ingot is then rolled off the mandrel, so that the length of the mandrel does not impose a limit upon the length of the rolled tubes.
• a mandrel with a tapered front end.
• the tapered end cooperates particularly with the rolls as they roll the tube off the tapered portion of the mandrel.
• rolls itself is per so not a significant aspect within the context of this invention.
• Known rolling equipment can readily be used and adapted for practicing the invention.
• Rolls can be used as employed in regular skew rolling mills for piercing mills or in tube expanding rolling mills.
• Rolls that are usable are particularly disclosed in German Pat. No. 646,162.
• the present invention is particularly directed to tube rolling mills of that type, such as an tube expander rolling mill, as disclosed in that German Pat. No. 646,162.
• the mill is to have at least three rolls, which (a) operate in common plane (b) are not at right angles to the direction of rolling, (c) roll on the hollow ingot for stretching and draw rolling of the continuously cast ingot, whereby the ingot is restrained from turning on its axis, in a manner as is, for example, known per se and used in rod erecting machines.
• Method of stretching a continuously cast hollow ingot as cut from the casting by means of hot rolling comprising the steps of:
• Method as in claim 1 including the step of disposing the hollow ingot upon a cylindrical mandrel in loose, clearing relation; rolling the ingot oi? the mandrel; and gradually withdrawing the mandrel during the rolling.
• Method as in claim 1 including the employment of a mandrel having a cylindrical portion and a tapered portion, the ingot being disposed upon the cylindrical portion of the mandrel, the ingot being rolled off the tapering portion of the mandrel, the tapered portion remains stationary, relative to the axes of the rolls.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Metal Rolling (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=25757818

Family Applications (1)

Country Status (5)

Cited By (4)

• 0
  • BE BE754607D patent/BE754607A/xx unknown
• 1969
  • 1969-08-18 DE DE19691942589 patent/DE1942589A1/de active Pending
• 1970
  • 1970-07-23 AT AT676670A patent/AT304416B/de not_active IP Right Cessation
  • 1970-08-10 US US62640A patent/US3673836A/en not_active Expired - Lifetime
  • 1970-08-14 FR FR7029984A patent/FR2058083A5/fr not_active Expired

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