Classifications

• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
  • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
  • C21D8/06—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of rods or wires
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES, PROFILES OR LIKE SEMI-MANUFACTURED PRODUCTS OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
  • B21C9/00—Cooling, heating or lubricating drawing material
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C38/00—Ferrous alloys, e.g. steel alloys
  • C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese

Definitions

• the invention also includes the tough high-strength killed low alloy ferritic steel wire produced by said process.
• High-strength small-gauge wire for example, tire reinforcing wire, is generally produced from a carbon steel containing 0.70% C., 0.20% Si and 0.60% manganese.
• the wire drawing process for the production of the aforesaid high-strength high carbon wire involves a continuous heat treatment requiring two stages before each cycle of wire drawing.
• the foregoing treatment, which is also performed on the rolled starting wire, is called patenting.
• the wire is austenitized over the A point between 900950 C. and is then immediately converted at a temperature of approximately 500 C.
• a continuous conveyor furnace with air or combustion gas atmosphere is usually utilized for the austenitizing.
• the conversion is usually in a bath furnace, usually with a molten lead bath.
• the wire surface is normally oxidized and this oxide must be removed prior to the next wire drawing step.
• the oxide is usually removed by pickling in sulfuric or hydrochloric acid.
• the wire is then drawn with maximum reduction per drawing down to a dimensions somewhat larger than the dimension where material brittleness occurs.
• the wire is then again patented and cycles of patenting/drawing repeated until the desired wire product dimension is obtained.
• the present invention provides a process for producing high-strength steel small-gauge wire having a diameter up to 1 millimeter comprising reducing the diameter of a killed low alloy steel rolled starting wire, said steel containing between about 0.01 and 0.06% carbon, between about 0.05 and 1% silicon, between about 0.25 and 6% manganese, between about 0.01 and 0.30% niobium, up to 0.03% nitrogen, up to 0.2% aluminum, up to 0.5 zirconium, up to 0.30% vanadium, and up to 0.5% titanium, by sequential passes through drawing dies constituting a drawing cycle, followed by tempering at a temperature between about 400 C. and 670 C., and further reduction with at least one additional drawing cycle, with tempering at a temperature between about 400 C. and 670 C. between each drawing cycle, until the product wire dimension is obtained.
• the present invention further provides a tough highstrength killed low alloy ferritic steel small-gauge wire having a diameter up to 1 millimeter, said steel wire consisting essentially of between about 0.01 and 0.06% carbon, between about 0.05 and 1% silicon, between about 0.25 and 6% manganese, between about 0.01 and 0.30% niobium, up to 0.03% nitrogen, up to 0.2% aluminum, up to 0.5 zirconium, up to 0.30% vanadium, and up to 0.5 titanium, said steel wire having a resistance to rupture of up to about 275 kg./n1m. and an elongation of at least about 2% on a measured length of 200 millimeters.
• the heat treatment between successive drawing cycles consists of tempering within the temperature range of about 400-670 C. Said heat treatment may be carried out more simply and using less expensive heat treatment equipment than in the patenting process. Continuous heat treatment is most suitable, e.g., high frequency heating or direct resistance heating. These two methods used in combination with the drawing eliminate the treating time of two separate heat treatments and certain of the costs incident thereto.
• the heat treatment can also although it is less attractive be carried out in soaking pits bath-furnaces or bell-type furnaces.
• Protective atmosphere equipment can readily be used in conjunction with high frequency heating or with direct resistance heating, thereby substantially avoiding oxidation and minimizing the possible use of pickling and often making pickling unnecessary.
• the protective atmosphere may be a conventional nonoxidizing atmosphere of the type used in heat treating steel at the temperatures specified.
• the wire product having the aforesaid composition is ferritic. It is substantially free of pearlite. As a result, the notch effect resultant from inclusions is considerably lower than that of conventional carbon steel wire. Because of the steel wires aforesaid structure, the steel exhibits a slow rate of strain hardening during working with the consequence that it is possible to perform large reductions per drawing and a large total reduction during a drawing cycle.
• drawing cycle is used to designate sequential drawings of the wire without intermediate heat treatment. Heat treatment is effected between successive drawing cycles. As a result of the low carbon content of the wire, there is no risk of'decarburization during processing. On the contrary, carburization must be avoided. Carburization is avoided more simply than the procedures requisite to avoid decarburization.
• the process of the present invention has the additional advantage that it is not necessary to heat treat the rolled starting wire before the firstd rawing cycle.
• the invention is further illustrated in the following example in which rolled wire stock (referred to herein as starting wire) having an initial diameter of 5.6 millimeters (mm.) is drawn to small-gauge wire having a diameter of 0.15 mm.
• the initial rolled steel wire had an analysis of 0.03% C., 0.25% Si, 3.5% Mn, 0.10% Nb, and 0.010% N.
• the first drawing cycle with 30-35% re- "duction per drawing (by passing through a drawing die) reduced the initial rolled Wire to a diameter of 1.50 mm. It was then tempered. Th drawing cycle utilized reductions of approximately -25% per drawing.
• the second drawing cycle reduced the diameter to 0.43 mm., with the third drawing cycle reducing the diameter to the finished diameter of 0.15 mm.
• a test of the toughness by means of the socalled loop test was satisfactory. In the said loop test, the wire is looped and the loop is contracted to a tie which must not cause breakage of the wire until a certain specified age.
• Similar high-strength tough wire as for the exemplified wire is produced from the other steel compositions within the ranges specified.
• Such wire is particularly useful for producing a wire rope, and wire reinforcement for a variety of industrial products, e.e., tires and hoses.
• the process advantages include the absence of the lead bath with the consequent health, cleanliness and safety problems.
• the process for producing high-strength steel smallgauge wire having a diameter up to 1 millimeter said steel wire being a killed low alloy steel consisting essentially of between about 0.01 and 0.06% carbon, between about 0.05 and 1% silicon, between about 0.25 and 0.75% manganese, between about 0.01 and 0.30% niobium, up to 0.03% nitrogen, up to 02% aluminum, up to 0.5% zirconium, up to 0.3% vanadium, and up to 0.5% titanium, comprising reducing a rolled starting wire to the final dimension in one drawing cycle without any heat treatment.
• a killed low alloy steel consisting essentially of between about 0.01 and 0.06% carbon, between about 0.05 and 1% silicon, between about 0.25 and 0.75% manganese, between about 0.01 and 0.30% niobium, up to 0.03% nitrogen, up to 02% aluminum, up to 0.5% zirconium, up to 0.3% vanadium, and up to 0.5% titanium, comprising reducing a rolled starting wire to the final dimension
• a tough high-strength killed low alloy ferritic steel small-gauge wire having a diameter up to 1 millimeter, said steel wire consisting essentially of between about 0.01 and 0.06% carbon, between about 0.05 and 1% silicon, between about 0.25 and 6% manganese, between about 0.01 and 0.30% niobium, up to 0.03% nitrogen, up to 0.2% aluminum, up to 0.5% Zirconium, up to 0.30% vanadium, and up to 0.5 titanium, said steel wire having a resistance to rupture of up to about 275 kg./mm. and an elongation of at least about 2% on a measured length of 200 millimeters.
• the tough high-strength small-gauge wire of claim 7 consisting essentially of 0.03% carbon, 0.25% silicon,
• the tough high-strength small-gauge wire of claim 7 having a manganese content of between about 0.25 and 0.75%.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Mechanical Engineering (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Manufacturing & Machinery (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Crystallography & Structural Chemistry (AREA)
• Heat Treatment Of Strip Materials And Filament Materials (AREA)
• Heat Treatment Of Steel (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=20257905

Family Applications (1)

Country Status (8)

Cited By (13)

Families Citing this family (4)

• 1970
  • 1970-02-11 SE SE01272/70A patent/SE335547B/xx unknown
• 1971
  • 1971-01-13 BE BE761518A patent/BE761518A/xx unknown
  • 1971-01-14 GB GB178371A patent/GB1325852A/en not_active Expired
  • 1971-01-21 US US108592A patent/US3674570A/en not_active Expired - Lifetime
  • 1971-01-27 CH CH121771A patent/CH542004A/de not_active IP Right Cessation
  • 1971-02-01 AT AT78371A patent/AT317820B/de not_active IP Right Cessation
  • 1971-02-01 FR FR7103302A patent/FR2078026A5/fr not_active Expired
  • 1971-02-02 DE DE19712104771 patent/DE2104771A1/de active Pending

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