Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES, OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
  • B21C1/00—Manufacture of metal sheets, metal wire, metal rods, metal tubes by drawing
  • B21C1/003—Drawing materials of special alloys so far as the composition of the alloy requires or permits special drawing methods or sequences
• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
  • D07B1/00—Constructional features of ropes or cables
  • D07B1/06—Ropes or cables built-up from metal wires, e.g. of section wires around a hemp core
  • D07B1/0606—Reinforcing cords for rubber or plastic articles
  • D07B1/066—Reinforcing cords for rubber or plastic articles the wires being made from special alloy or special steel composition
• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
  • D07B2205/00—Rope or cable materials
  • D07B2205/30—Inorganic materials
  • D07B2205/3021—Metals
  • D07B2205/3025—Steel
  • D07B2205/3035—Pearlite
• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
  • D07B2205/00—Rope or cable materials
  • D07B2205/30—Inorganic materials
  • D07B2205/3021—Metals
  • D07B2205/3025—Steel
  • D07B2205/3046—Steel characterised by the carbon content
  • D07B2205/3057—Steel characterised by the carbon content having a high carbon content, e.g. greater than 0,8 percent respectively SHT or UHT wires
• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
  • D07B2501/00—Application field
  • D07B2501/20—Application field related to ropes or cables
  • D07B2501/2046—Tire cords

Definitions

• the present invention relates to a method of manufacturing a steel wire (hereinafter, also simply referred to as “manufacturing method”), and more particularly, to a method of manufacturing a steel wire that can reduce energy required for manufacturing the steel wire.
• Steel cords made of twisted steel strands are used as reinforcing materials for rubber articles such as tires.
• the high carbon steel wire used for this steel wire etc. is conventionally manufactured by the following processes.
• Such a high carbon steel wire is made from a high carbon steel wire having a diameter of about 5.5 mm, which is made into a pearlite structure by a stealmore treatment.
• the raw material is drawn to obtain an intermediate wire larger than the final diameter.
• dry-type drawing is generally applied, and in some cases, two-step drawing with heat treatment interposed is applied.
• the intermediate wire is subjected to a patenting heat treatment to obtain a heat-treated wire having a fine pearlite structure, and when producing a strand for reinforcing rubber articles, a brass plating treatment is performed following the heat treatment. .
• the heat-treated wire is drawn to obtain a steel wire having a desired final diameter and a desired tensile strength.
• the wet wire drawing method is applied to the final wire drawing.
• the tensile strength of the steel wire produced in the above process is greatly affected by the composition of raw materials (mainly carbon content) and the amount of wire drawing in the final wire drawing process. That is, the higher the carbon content and the greater the amount of wire drawing in the final wire drawing step, the higher the tensile strength of the steel wire.
• the carbon content of a raw material generally used for manufacturing a steel cord strand is 0.80 to 0.86% by mass (hereinafter referred to as “80C material”).
• 80C material the carbon content of a raw material generally used for manufacturing a steel cord strand.
• the following formula, ⁇ f 2ln (D0 / Df) (Where Df represents the final diameter of the steel wire obtained in the final wire drawing process, D0 represents the diameter of the heat-treated wire before the final wire drawing, and ln is a natural logarithm).
• the wire drawing amount ⁇ f in the final wire drawing step is about 3.2 when a steel wire having a diameter of 0.23 mm and a tensile strength of about 3200 MPa is manufactured using such raw materials.
• a technique for increasing the strength and a technique for further reducing the manufacturing cost have been demanded.
• Patent Documents 1 to 4 disclose techniques for improving tensile strength by using 80C material and improving final wire drawing conditions to increase the final wire drawing amount.
• Patent Documents 5 and 6 disclose a technique for improving tensile strength by adjusting a wire drawing amount in a pre-drawing process for producing an intermediate wire using a raw material having an increased carbon content. Yes.
• Patent Document 7 discloses a technique for improving tensile strength by using a raw material having an increased carbon content and adding an alloy element such as Cr.
• Patent Documents 8 and 9 a steel wire having a tensile strength equivalent to that obtained when the 80C material is applied by using a raw material having a carbon content smaller than that of the 80C material and increasing the final wire drawing amount is manufactured. Techniques to do this are disclosed.
• JP-A-8-132128 (Claims etc.) JP-A-8-218282 (Claims etc.) Japanese Patent Laid-Open No. 10-325089 (Claims etc.) Japanese Patent Laid-Open No. 11-241280 (claims, etc.) JP-A-6-136453 (claims, etc.) Japanese Unexamined Patent Publication No. 2007-111767 (Claims etc.) JP 2008-69409 A (Claims etc.) JP-A-8-260096 (Claims etc.) JP-A-8-325964 (Claims etc.)
• an object of the present invention is to provide a manufacturing method capable of solving a problem in the above prior art and manufacturing a steel wire having a good tensile strength with a small processing energy. Specifically, it is to provide a production method capable of producing a steel wire having a tensile strength equivalent to that of a steel wire obtained by a conventional general production method using 80C material with a small processing energy.
• the present inventor has obtained the following knowledge. That is, in the final wire drawing, a wet slip wire drawing method is usually employed, but the wire drawing method of the wet wire drawing is a method of drawing a wire with a capstan in a lubricating liquid.
• the wire drawing method of the wet wire drawing is a method of drawing a wire with a capstan in a lubricating liquid.
• a speed difference that is, a slip is required between the capstan and the wire, and this slip causes a loss of production power.
• the dry-type wire drawing machine used for pre-drawing has a knowledge that the speed is controlled by one motor per capstan, so that slip does not occur and production power loss is small. .
• the friction coefficient is large because the die interface is in an extreme pressure lubrication state where the wire surface is plated and metal touched.
• dry wire drawing is considered to have a low friction coefficient because a powdery lubricant is drawn into the die interface and the lubricant dissolves, resulting in a fluid lubrication state.
• the wet wire drawing consumes more power than the dry wire drawing. Therefore, as a result of further diligent examination based on such knowledge, the present inventor has adjusted the wire drawing amount ⁇ f in the final wire drawing process to reduce the steel wire having a good tensile strength to a small processing energy. As a result, the present invention has been completed.
• the method for producing a steel wire of the present invention includes a pre-drawing step of drawing a high carbon steel wire containing 0.90 to 1.20% by mass of carbon into an intermediate wire, and the intermediate wire.
• a method of manufacturing a steel wire including a heat treatment step of performing a patenting heat treatment to obtain a heat-treated wire, and a final wire drawing step of drawing the heat-treated wire to obtain a steel wire
• the wire drawing amount ⁇ f in the final wire drawing step is 2.50 to 3.10.
• the metal structure of the high carbon steel wire is preferably pearlite, and the diameter of the steel wire obtained in the final wire drawing step is 0.05 to 0.00.
• the method for producing a steel wire of the present invention includes a tensile strength TSf of the steel wire obtained in the final wire drawing step, a tensile strength TS of the heat-treated wire, and the ⁇ f. Is the following formula: TS ⁇ exp (0.24 ⁇ ⁇ f) ⁇ TSf ⁇ TS ⁇ exp (0.30 ⁇ ⁇ f) It is preferable to satisfy the relationship represented by: TSf is more preferably 2700 to 3300 MPa.
• a high carbon steel wire containing 0.90 to 1.05% by mass of carbon is drawn to obtain an intermediate wire, and the ⁇ f is set to 2.70 to 3. 05, and the TSf is preferably 2700-3200 MPa.
• the method for producing a steel wire of the present invention includes a pre-drawing step for drawing a high carbon steel wire to an intermediate wire, a heat treatment step for subjecting the intermediate wire to a patenting heat treatment to a heat-treated wire, And a final drawing step of drawing the heat-treated wire to obtain a steel wire.
• the method for producing a steel wire of the present invention uses a high carbon steel wire containing 0.90 to 1.20% by mass of carbon as a raw material, and Cr, Ni, V, etc. are used as the high carbon steel wire.
• a raw material to which the alloy element is added may be used. If the amount of carbon contained in the high carbon steel wire is less than 0.90% by mass, the required amount of processing in the final wire drawing process cannot be set much lower than when a general 80C material is applied. Is small. On the other hand, when it exceeds 1.20% by mass, it becomes difficult to obtain a uniform metal structure in the heat treatment step, and the wire drawing workability of the heat-treated wire is inferior.
• the wire drawing amount ⁇ f in the final wire drawing step is 2.50 to 3.10, preferably 2.60 to 3.00.
• the drawing amount ⁇ f is less than 2.50, it is difficult to obtain a tensile strength desired as a rubber reinforcing wire or a rope wire.
• the amount of wire drawing ⁇ f exceeds 3.10, the energy required for the final wire drawing increases, making it difficult to obtain an energy saving effect.
• the energy consumed in the production of steel wire is large in the proportion of power required for the final wire drawing process. Therefore, by adjusting the wire drawing amount ⁇ f in the final wire drawing step, a steel wire having a good tensile strength can be manufactured with a small amount of processing energy.
• the amount of wire drawing required in the final wire drawing process to obtain the same tensile strength as that of the conventional product can be reduced. It is possible to reduce the energy required for this.
• reducing the final wire drawing amount is advantageous for improving the ductility of the steel wire, and can be expected to have accompanying effects such as an improvement in productivity due to a reduction in disconnection and an improvement in the quality of the steel wire.
• the metal structure of the high carbon steel wire is preferably pearlite. This is because pearlite steel has a higher work hardening rate than martensite steel.
• the diameter of the steel wire obtained in the final wire drawing step is preferably 0.05 to 0.50 mm. This range is a desirable diameter range for rubber reinforcement and rope strands, and a steel wire having good tensile strength can be produced with less processing energy.
• the tensile strength TSf of the steel wire obtained in the final wire drawing step, the tensile strength TS of the heat-treated wire, and ⁇ f are expressed by the following equations: TS ⁇ exp (0.24 ⁇ ⁇ f) ⁇ TSf ⁇ TS ⁇ exp (0.30 ⁇ ⁇ f) It is preferable to satisfy the relationship represented by: TSf is more preferably 2700 to 3300 MPa. If the tensile strength of the steel wire is less than 2700 MPa, the strength may be insufficient as a strand for rubber reinforcement or rope. On the other hand, if the tensile strength of the steel wire exceeds 3300 MPa, the carbon content is increased. This is because it is necessary to set a large amount of processing in the final wire drawing process, which may reduce the energy saving effect.
• a high carbon steel wire containing 0.90 to 1.05% by mass of carbon is drawn to obtain an intermediate wire, and the drawing amount ⁇ f is 2.70.
• the tensile strength of the steel wire obtained in the final wire drawing step is preferably 2700 to 3200 MPa. Thereby, the steel wire which has favorable tensile strength can be manufactured with less processing energy. Moreover, it becomes easy to obtain a uniform metal structure in the heat treatment step by setting the upper limit of the amount of carbon contained in the high carbon steel wire to 1.05.
• the carbon content in the high carbon steel wire, the wire drawing amount ⁇ f, and the tensile strength of the steel wire obtained in the final wire drawing step are important.
• it can carry out suitably according to a conventional method as desired, and it does not restrict
• the steel wire manufacturing method of the present invention can be used for manufacturing steel cord strands for reinforcing rubber articles, wire rope strands, and the like.
• Example 1 Diameter 5.5.
• An intermediate wire was produced by drawing a high carbon steel wire (102C material) containing 1.02 mass% of carbon in mm (pre-drawing step). The pre-drawing step was performed without intermediate heat treatment.
• the obtained intermediate wire was subjected to patenting heat treatment to produce a heat-treated wire (heat treatment step, heat treatment plating).
• the heat treated wire was subjected to wire drawing (final wire drawing step) to obtain a steel wire of Example 1 having a diameter of 0.19 mm and a tensile strength TSf of 3000 MPa.
• the metal structure of the high carbon steel wire used is a substantially uniform pearlite structure.
• Table 1 below shows the manufacturing conditions of Example 1, the intermediate wire diameter (mm), the amount of wire drawing ⁇ in the previous wire drawing step, the tensile strength (TS, unit MPa) of the heat-treated wire, and the final The final diameter (mm) of the steel wire obtained in the wire drawing step, the drawing amount ⁇ f in the final wire drawing step, and the tensile strength (TSf, unit MPa) of the steel wire obtained in the final wire drawing step are shown. .
• Table 1 shows the carbon content (mass%), diameter (mm), and material abbreviations of the raw materials used.
• Example 2 A steel wire of Example 2 having a diameter of 0.19 mm and a TSf of 3000 MPa was obtained in the same manner as Example 1 except that the production conditions shown in Table 1 were used.
• Comparative Example 1 A steel wire of Comparative Example 1 having a diameter of 0.19 mm and a TSf of 3000 MPa was obtained in the same manner as in Example 1 except that the production conditions shown in Table 1 were used.
• Comparative Example 2 The 90C material was processed using the manufacturing conditions shown in the conventional example to obtain a steel wire of Comparative Example 2 having a diameter of 0.19 mm and a TSf of 3350 MPa.
• Comparative Example 3 A steel wire of Comparative Example 3 having a diameter of 0.19 mm and a TSf of 3000 MPa was obtained in the same manner as in Example 1 except that the production conditions shown in Table 1 were used.
• the ratio of the required energy in the final wire drawing process was large.
• the required energy in the final wire drawing process of the high carbon steel material can be reduced.
• the steel wire with good tensile strength can be produced with less processing energy.
• steel wires having a diameter of 0.19 mm and a steel wire having a tensile strength of 3000 and 3350 MPa are given as examples. However, the same effect can be obtained in the manufacture of steel wires having different diameters or tensile strengths of steel wires. Can be obtained.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Metal Extraction Processes (AREA)
• Heat Treatment Of Steel (AREA)

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• 2010
  • 2010-03-02 CN CN2010800104871A patent/CN102341194A/zh active Pending
  • 2010-03-02 JP JP2011502765A patent/JP5701744B2/ja not_active Expired - Fee Related
  • 2010-03-02 US US13/254,308 patent/US20110314888A1/en not_active Abandoned
  • 2010-03-02 WO PCT/JP2010/053352 patent/WO2010101154A1/ja active Application Filing
  • 2010-03-02 EP EP10748749.8A patent/EP2404681B1/de not_active Not-in-force

Patent Citations (9)

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