Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21B—ROLLING OF METAL
  • B21B1/00—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations
  • B21B1/16—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling wire rods, bars, merchant bars, rounds wire or material of like small cross-section
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21B—ROLLING OF METAL
  • B21B45/00—Devices for surface or other treatment of work, specially combined with or arranged in, or specially adapted for use in connection with, metal-rolling mills
  • B21B45/04—Devices for surface or other treatment of work, specially combined with or arranged in, or specially adapted for use in connection with, metal-rolling mills for de-scaling, e.g. by brushing
• • 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
  • Y10T29/45—Scale remover or preventor
  • Y10T29/4517—Rolling deformation or deflection
  • Y10T29/4522—Rolling deformation or deflection for wire or rod
• • 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
  • Y10T29/45—Scale remover or preventor
  • Y10T29/4533—Fluid impingement
  • Y10T29/455—Airblast
• • 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
  • Y10T29/49982—Coating
  • Y10T29/49986—Subsequent to metal working
• • 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

• the invention relates to a method for producing bright steel, in particular rod-shaped bright round steel produced from hot-rolled steel.
• Bright steel, especially bright round steel, is a rolled or forged steel bar with a bright metallic surface.
• the surface quality is usually divided into technical quality classes, for example in accordance with DIN 668.
• the bright metallic surface of the steel is conventionally produced by peeling or bright drawing.
• Bright drawing is a process for the production of drawn steel, in which the oxide layer is removed from the surface and cold cutting is carried out without cutting.
• the stands suitable for this are drawing-rolling mills, in which a rolled-up rolling stock is drawn through the non-driven rolls of a rolling stand.
• Drawing benches which are equipped with appropriately shaped drawing tools are also known as a suitable machine tool for producing bright steel.
• the peeling of the round steel to produce a bare surface is a machining operation and takes place on so-called peeling machines, which are equipped with appropriately shaped peeling knives, as well as with guide and drive rollers.
• the peeling of the round steel is a measure that is always associated with material loss is, even if it is steel grades that have not undergone edge decarburization and, viewed in this way, do not necessarily have to be treated with material removal.
• the investment costs for a drawing roller mill, for a drawing bench or for a peeling machine are high, as are the running tool costs for peeling knives, guide and drive rollers, etc.
• the discontinuous operation during drawing and the requirements of upstream and downstream equipment involve the integration of the above-mentioned processing machines in the layout of flow adjustment.
• the object of the invention is to avoid the disadvantages of peeling or drawing, in particular, of rolled round steel to produce its bare metal surface, and to provide a method with which bright round steel can be produced directly from hot-rolled round steel, using equipment, which are already available in post-treatment lines for round steel production.
• the inventive method is characterized in that the round steel from the rolling heat in a sizing mill is rounded to close tolerances, that the oxide layer of the round steel is largely removed, and that the round steel is then subjected to a directional polishing process. It was surprisingly found that with the proposed measures a round steel with a bright surface can be produced, the surface quality of which is comparable to the surface quality of bright drawn or peeled round steel. Bending tests of the bare round steel produced according to the invention also showed no deviations from peeled or drawn material. It can be emphasized as a significant economic advantage that the bright round steel produced with the proposed method corresponds to the relevant DIN regulations according to the individual quality classes.
• the round steel is rolled in a high-precision rolling mill except for a roundness between 0.01% and 0.1%. It has proven to be an advantage if the rolling tolerance with regard to the out-of-roundness is within the proposed tolerance limits, ie that the rolled steel should already be as round as possible so that the final directional polishing process in a directional polishing machine is not impaired. If the tolerance limits for out-of-roundness are adhered to, then the straightening rollers of the straightening machine will not vibrate and thus prevent the surface from being adversely affected, for example by chatter marks.
• the proposed method is advantageously further developed by descaling the surface of the round steel to a degree of descaling corresponding to class A Sa 2.5 according to SVENSK STANDARD SIS 05 59 00 - 1967.
• the rolling material must also be as free from scale as possible, so that rust and foreign bodies are removed so completely that residues only appear as shades or stripes. This requirement can advantageously be met if the round steel is descaled in a centrifugal wheel descaling system.
• a wire grain with a diameter of 0.4 to 0.8 mm, preferably 0.6 mm is used as the blasting agent for descaling the round steel in the centrifugal wheel descaling system.
• an abrasive of the proposed selection an optimal descaling of the surface of the round steel is achieved without scarring it. It is within the scope of the invention if the round steel is treated on its surface by pickling, bright annealing or the like before the directional polishing process.
• the surface roughness R Z of the round steel - defined as the mean value of the absolute values of the heights of the five highest profile crests and the absolute values of the depths of the five deepest profile valleys within the reference distance - in the directional polishing machine to values between 1 ⁇ ⁇ R Z ⁇ 8 ⁇ is set.
• the contact forces and the straightening forces of the rollers of the straightening polishing machine can be adjusted to the extent that the proposed values for the surface roughness can be easily adhered to.
• the values set with the directional polishing machine for the Surface roughness makes the round steel appear bright on the outside, making the surface of the round steel suitable for further processing. Tests have also shown that if the proposed out-of-roundness is not exceeded in the rolling process, this out-of-roundness is additionally reduced by the order of 20 to 30% in the subsequent directional polishing process.
• a hot-rolled round steel bar with a diameter of 22 mm was rolled in a last pass in a high-precision rolling mill and an out-of-roundness was observed after the three-point measurement of 0.09 mm.
• This round steel was then descaled to a descaling degree of A Sa 2.5 in accordance with the Swedish standard SIS 05 59 00 - 167 in a commercial centrifugal wheel descaling system using a wire grain of 0.6 mm as blasting media.
• the descaled round steel was then subjected to a leveling process in a leveling machine.
• the measured surface roughness R Z was 2.22 ⁇ .
• the maximum profile depth R m ie the distance of the deepest point of the surface profile from the center line within the reference distance, was 3.52 ⁇ .
• the arithmetic mean roughness Ra of the absolute values of the profile deviations within the reference distance was 0.24 ⁇ . All values were evaluated in accordance with DIN 47 62.
• the bare round steel thus produced corresponded to the quality class DIN 668.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Metal Rolling (AREA)
• Heat Treatment Of Steel (AREA)
• Wire Processing (AREA)
• Heat Treatment Of Articles (AREA)
• Control Of Metal Rolling (AREA)
• Finish Polishing, Edge Sharpening, And Grinding By Specific Grinding Devices (AREA)
• Metal Extraction Processes (AREA)

Applications Claiming Priority (2)

Publications (3)

Family

ID=6414615

Family Applications (1)

Country Status (5)

Families Citing this family (3)

Citations (3)

Family Cites Families (20)

• 1990
  • 1990-09-20 DE DE4029786A patent/DE4029786A1/de not_active Withdrawn
• 1991
  • 1991-09-07 DE DE59103782T patent/DE59103782D1/de not_active Expired - Fee Related
  • 1991-09-07 EP EP91115166A patent/EP0476467B1/fr not_active Expired - Lifetime
  • 1991-09-07 AT AT91115166T patent/ATE115013T1/de not_active IP Right Cessation
  • 1991-09-19 JP JP3239915A patent/JPH04244367A/ja not_active Withdrawn
• 1993
  • 1993-04-12 US US08/046,518 patent/US5355570A/en not_active Expired - Fee Related

Patent Citations (3)

Non-Patent Citations (5)

Also Published As

Similar Documents

Legal Events