Classifications

• • 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
  • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
  • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
• • 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
• • 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
  • C21D8/065—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of rods or wires of ferrous alloys

Definitions

• a second cold drawing step reduces its cross sectional area at least 40% with the total reduction being at least 85% of the cross sectional area of the hot rolled rod.
• the product may then be stress relieved at a temperature between 850 and 1200 F.
• the stainless steel wire so produced has a minimum tensile strength of 300,000 lbs. per sq. in. and is capable of withstanding at least 25 twists in a length of wire 100 times its diameter.
• This invention relates to stainless steel wire products and to a method of making the same, and particularly relates to austenitic stainless steels containing 17 to 20% chromium, 7 to 10% nickel, and .03 to .70% carbon.
• Stainless Steel Types 302 and 304 are in this category. Such steels are made into wire which in many cases is used to make wire rope. Wire of this type, produced in the normal manner is very poor in torsion. Wire rope should also have high tensile strength and good ductility, which properties are not particularly good when the steels of the above type are processed in the usual manner.
• Another object is to provide a method of making a stainless steel wire rope with wire having high torsional properties and high tensile strength.
• a still further object is to provide a stainless steel wire product having good ductility, high torsional properties and high tensile strength.
• an elongated austenitic stainless steel member having the composition disclosed above and which has been processed in the usual manner.
• This member may be a hot rolled rod which has been cooled after hot rolling in such a manner that it is essentially in an annealed state, or it may be processed wire which has been annealed in the usual manner.
• I first subject this member to a cold drawing step in which its cross-sectional area is reduced between 30 and 75%. I find it necessary to have a minimum reduction of 30% in order that the product will not be too brittle for the further drawing operation discussed below. On the other hand, if the reduction is above 75%, costs will increase due to drawing difiiculties and heat treating without obtaining any further improvement.
• the drawn member is then stress relieved at a temperature between 850 and 1200 F. Subsequently, it is subjected to a second cold drawing step in which its crosssectional area is reduced at least 40%.
• the total reduction in the two drawing steps must be at least 85 of the cross sectional area of the starting member.
• a Type 304 annealed wire of .135" diameter was given a reduction to .068" and was then stress relieved for 6 hours at 925 F.
• This wire was then given a 75% reduction to a diameter of .034" so that there was an overall reduction in area of approximately 93.7%.
• the wire so produced had a tensile strength of 344,000 pounds per square inch and 76 twists in 8".
• This Wire was then' processed in the usual manner to make a Regular Lay 6 x 36 wire rope with an independent wire rope core, and the wire rope so formed was then stress relieved by heating it to a temperature of 1000 F.
• This wire rope had a breaking strength of 67,000 pounds.
• a similar wire rope, without the final stress relieving step had a breaking strength of 55,000 pounds. This compares with a breaking strength of 44,000 pounds for a similar rope processed in a conventional manner.
• the wire produced above when given a final stress relief at 1000 F., had a tensile strength of 358,000 p.s.i. and 93 twists in 8".
• a wire of the same size and composition produced in a conventional manner had a tensile strength of 290,000 pounds per square inch and between 14 and 40 turns in 8".
• wire reduced by drawing according to my invention will have a minimum tensile strength of 300,000 pounds per square inch and can be given a minimum of 25 twists in a length of wire times the wire diameter, before breaking.
• the tensile strength will increase as the amount of total reduction increases. In all cases the torsion properties will be at least as good as the minimum stated above.
• Other examples of Type 304 stainless wires made according to my invention, without a final stress relieving are as follows:
• the method of making stainless steel wire having high torsional properties, good ductility and high tensile strength which comprises providing an elongated austenitic stainless steel member containing 17 to 20% chromium, 7 to 10% nickel and .03 to .70% carbon, cold drawing said member to reduce its cross sectional area between 30 and 75%, then stress relieving said drawn member at a temperature of between 850 and 1200 F., then cold drawing said member to reduce its cross sectional area at least 40% with the total reduction being at least 85% of the cross sectional area of the starting member.
• the method of claim 3 including the step of stress relieving the wire rope at a temperature between 850 and 1200 F.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (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 Steel (AREA)
• Ropes Or Cables (AREA)
• Heat Treatment Of Strip Materials And Filament Materials (AREA)

Priority Applications (6)

Applications Claiming Priority (1)

Publications (1)

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Cited By (19)

Families Citing this family (2)

Citations (5)

• 1966
  • 1966-02-11 US US533116A patent/US3395528A/en not_active Expired - Lifetime
• 1967
  • 1967-01-30 DE DE1967U0013510 patent/DE1558669B2/de active Granted
  • 1967-01-30 GB GB4446/67A patent/GB1129869A/en not_active Expired
  • 1967-02-06 BE BE693701D patent/BE693701A/xx unknown
  • 1967-02-07 FR FR93910A patent/FR1510513A/fr not_active Expired
  • 1967-02-07 JP JP748067A patent/JPS543805B1/ja active Pending

Patent Citations (5)

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