Process for manufacturing steel filament

Claim 2

A process for manufacturing steel filament which has an outstanding combination of strength and ductility which comprises the sequential steps of (1) heating a steel wire in a first patenting step to a temperature which is within the range of about 900° C. to about 1100° C. for a period of at least about 5 seconds, wherein said steel wire consists essentially of (a) about 96 to about 99.1 weight percent iron, (b) about 0.6 to about 1 weight percent carbon, (c) about 0.1 to about 1.2 weight percent manganese, (d) about 0.1 to about 1 weight percent silicon, and (e) about 0.1 to about 0.8 weight percent chromium; (2) rapidly cooling said steel wire to a temperature which is within the range of about 540° C. to about 620° C. within a period of less than about 4 seconds; (3) maintaining said steel wire at a temperature within the range of about 540° C. to about 620° C. for a period which is sufficient for the microstructure of the steel in the steel wire to transform to an essentially body centered cubic microstructure; (4) cold drawing the steel wire to a draw ratio which is sufficient to reduce the diameter of the steel wire by about 40 to about 80%: (5) heating the steel wire in a second patenting step to a temperature which is within the range of about 900° C. to about 1100° C. for a period of at least about 1 second; (6) rapidly cooling said steel wire to a temperature which is within the range of about 540° C. to about 620° C. within a period of less than about 4 seconds: (7) maintaining said steel wire at a temperature within the range of about 540° C. to about 620° C. for a period which is sufficient for the microstructure of the steel in the steel wire to transform to an essentially body centered cubic microstructure; and (8) cold drawing the steel wire to a draw ratio which is sufficient to reduce the diameter of the steel wire by about 60 to about 98% to produce said steel filament.

Claim 3

A process for manufacturing steel filament which has an outstanding combination of strength and ductility which comprises the sequential steps of (1) heating a steel wire in a first patenting step to a temperature which is within the range of about 900° C. to about 1100° C. for a period of at least about 5 seconds, wherein said steel wire consists essentially of (a) about 95.5 to about 99.05 weight percent iron, (b) about 0.6 to about 1 weight percent carbon, (c) about 0.1 to about 1.2 weight percent manganese, (d) about 0.1 to about 1 weight percent silicon, (e) about 0.1 to about 0.8 weight percent chromium and (f) about 0.05 to about 0.5 weight percent cobalt; (2) rapidly cooling said steel wire to a temperature which is within the range of about 540° C. to about 620° C. within a period of less than about 4 seconds; (3) maintaining said steel wire at a temperature within the range of about 540° C. to about 620° C. for a period which is sufficient for the microstructure of the steel in the steel wire to transform to an essentially body centered cubic microstructure; (4) cold drawing the steel wire to a draw ratio which is sufficient to reduce the diameter of the steel wire by about 40 to about 80%: (5) heating the steel wire in a second patenting step to a temperature which is within the range of about 900° C. to about 1100° C. for a period of at least about 1 second; (6) rapidly cooling said steel wire to a temperature which is within the range of about 540° C. to about 620° C. within a period of less than about 4 seconds: (7) maintaining said steel wire at a temperature within the range of about 540° C. to about 620° C. for a period which is sufficient for the microstructure of the steel in the steel wire to transform to an essentially body centered cubic microstructure; and (8) cold drawing the steel wire to a draw ratio which is sufficient to reduce the diameter of the steel wire by about 60 to about 98% to produce said steel filament.

Claim 4

A process for manufacturing steel filament which has an outstanding combination of strength and ductility which comprises the sequential steps of (1) heating a steel wire in a first patenting step to a temperature which is within the range of about 900° C. to about 1100° C. for a period of at least about 5 seconds, wherein said steel wire consists essentially of (a) about 95.5 to about 99.05 weight percent iron, (b) about 0.6 to about 1 weight percent carbon, (c) about 0.1 to about 1.2 weight percent manganese, (d) about 0.1 to about 1 weight percent silicon, (e) about 0.1 to about 0.8 weight percent chromium and (f) about 0.05 to about 0.5 weight percent cobalt; (2) rapidly cooling said steel wire to a temperature which is within the range of about 540° C. to about 620° C. within a period of less than about 4 seconds; (3) maintaining said steel wire at a temperature within the range of about 540° C. to about 620° C. for a period which is sufficient for the microstructure of the steel in the steel wire to transform to an essentially body centered cubic microstructure; (4) cold drawing the steel wire to a draw ratio which is sufficient to reduce the diameter of the steel wire by about 40 to about 80%: (5) heating the steel wire in a second patenting step to a temperature which is within the range of about 900° C. to about 1100° C. for a period of at least about 1 second; (6) rapidly cooling said steel wire to a temperature which is within the range of about 540° C. to about 620° C. within a period of less than about 4 seconds: (7) maintaining said steel wire at a temperature within the range of about 540° C. to about 620° C. for a period which is sufficient for the microstructure of the steel in the steel wire to transform to an essentially body centered cubic microstructure; and (8) cold drawing the steel wire to a draw ratio which is sufficient to reduce the diameter of the steel wire by about 60 to about 98% to produce said steel filament.

Claim 5

A process for manufacturing steel filament which has an outstanding combination of strength and ductility which comprises the sequential steps of (1) heating a steel wire in a first patenting step to a temperature which is within the range of about 900° C. to about 1100° C. for a period of at least about 5 seconds, wherein said steel wire consists essentially of (a) about 95.8 to about 99.3 weight percent iron, (b) about 0.40 to about 1 weight percent carbon, (c) about 0.1 to about 1.2 weight percent manganese, (d) about 0.1 to about 1 weight percent silicon, (e) about 0.05 to about 0.5 weight percent molybdenum and (f) about 0.05 to about 0.5 weight percent cobalt: (2) rapidly cooling said steel wire to a temperature which is within the range of about 540° C. to about 620° C. within a period of less than about 4 seconds; (3) maintaining said steel wire at a temperature within the range of about 540° C. to about 620° C. for a period which is sufficient for the microstructure of the steel in the steel wire to transform to an essentially body centered cubic microstructure; (4) cold drawing the steel wire to a draw ratio which is sufficient to reduce the diameter of the steel wire by about 40 to about 80%; (5) heating the steel wire in a second patenting step to a temperature which is within the range of about 900° C. to about 1100° C. for a period of at least about 1 second: (6) rapidly cooling said steel wire to a temperature which is within the range of about 540° C. to about 620° C. within a period of less than about 4 seconds: (7) maintaining said steel wire at a temperature within the range of about 540° C. to about 620° C. for a period which is sufficient for the microstructure of the steel in the steel wire to transform to an essentially body centered cubic microstructure; and (8) cold drawing the steel wire to a draw ratio which is sufficient to reduce the diameter of the steel wire by about 60 to about 98% to produce said steel filament.

Claim 6

A process for manufacturing steel filament which has an outstanding combination of strength and ductility which comprises the sequential steps of (1) heating a steel wire in a first patenting step to a temperature which is within the range of about 900° C. to about 1100° C. for a period of at least about 5 seconds, wherein said steel wire consists essentially of (a) about 95.8 to about 99.3 weight percent iron, (b) about 0.40 to about 1 weight percent carbon, (c) about 0.1 to about 1.2 weight percent manganese, (d) about 0.1 to about 1 weight percent silicon, (e) about 0.05 to about 0.5 weight percent molybdenum and (f) about 0.05 to about 0.5 weight percent cobalt: (2) rapidly cooling said steel wire to a temperature which is within the range of about 540° C. to about 620° C. within a period of less than about 4 seconds; (3) maintaining said steel wire at a temperature within the range of about 540° C. to about 620° C. for a period which is sufficient for the microstructure of the steel in the steel wire to transform to an essentially body centered cubic microstructure; (4) cold drawing the steel wire to a draw ratio which is sufficient to reduce the diameter of the steel wire by about 40 to about 80%; (5) heating the steel wire in a second patenting step to a temperature which is within the range of about 900° C. to about 1100° C. for a period of at least about 1 second: (6) rapidly cooling said steel wire to a temperature which is within the range of about 540° C. to about 620° C. within a period of less than about 4 seconds: (7) maintaining said steel wire at a temperature within the range of about 540° C. to about 620° C. for a period which is sufficient for the microstructure of the steel in the steel wire to transform to an essentially body centered cubic microstructure; and (8) cold drawing the steel wire to a draw ratio which is sufficient to reduce the diameter of the steel wire by about 60 to about 98% to produce said steel filament.

Claim 7

A process for manufacturing steel filament which has an outstanding combination of strength and ductility which comprises the sequential steps of (1) heating a steel wire in a first patenting step to a temperature which is within the range of about 900° C. to about 1100° C. for a period of at least about 5 seconds, wherein said steel wire consists essentially of (a) about 95.74 to about 99.09 weight percent iron, (b) about 0.6 to about 1 weight percent carbon, (c) about 0.1 to about 1.2 weight percent manganese, (d) about 0.1 to about 1 weight percent silicon, (e) about 0.01 to about 0.06 weight percent niobium (f) about 0.05 to about 0.5 weight percent molybdenum, and (g) about 0.05 to about 0.5 weight percent cobalt; (2) rapidly cooling said steel wire to a temperature which is within the range of about 540° C. to about 620° C. within a period of less than about 4 seconds; (3) maintaining said steel wire at a temperature within the range of about 540° C. to about 620° C. for a period which is sufficient for the microstructure of the steel in the steel wire to transform to an essentially body centered cubic microstructure; (4) cold drawing the steel wire to a draw ratio which is sufficient to reduce the diameter of the steel wire by about 40 to about 80%; (5) heating the steel wire in a second patenting step to a temperature which is within the range of about 900° C. to about 1100° C. for a period of at least about 1 second; (6) rapidly cooling said steel wire to a temperature which is within the range of about 540° C. to about 620° C. within a period of less than about 4 seconds; (7) maintaining said steel wire at a temperature within the range of about 540° C. to about 620° C. for a period which is sufficient for the microstructure of the steel in the steel wire to transform to an essentially body centered cubic microstructure; and (8) cold drawing the steel wire to a draw ratio which is sufficient to reduce the diameter of the steel wire by about 60 to about 98% to produce said steel filament.

Claim 8

A process for manufacturing steel filament which has an outstanding combination of strength and ductility which comprises the sequential steps of (1) heating a steel wire in a first patenting step to a temperature which is within the range of about 900° C. to about 1100° C. for a period of at least about 5 seconds, wherein said steel wire consists essentially of (a) about 95.74 to about 99.09 weight percent iron, (b) about 0.6 to about 1 weight percent carbon, (c) about 0.1 to about 1.2 weight percent manganese, (d) about 0.1 to about 1 weight percent silicon, (e) about 0.01 to about 0.06 weight percent niobium (f) about 0.05 to about 0.5 weight percent molybdenum, and (g) about 0.05 to about 0.5 weight percent cobalt; (2) rapidly cooling said steel wire to a temperature which is within the range of about 540° C. to about 620° C. within a period of less than about 4 seconds; (3) maintaining said steel wire at a temperature within the range of about 540° C. to about 620° C. for a period which is sufficient for the microstructure of the steel in the steel wire to transform to an essentially body centered cubic microstructure; (4) cold drawing the steel wire to a draw ratio which is sufficient to reduce the diameter of the steel wire by about 40 to about 80%; (5) heating the steel wire in a second patenting step to a temperature which is within the range of about 900° C. to about 1100° C. for a period of at least about 1 second; (6) rapidly cooling said steel wire to a temperature which is within the range of about 540° C. to about 620° C. within a period of less than about 4 seconds; (7) maintaining said steel wire at a temperature within the range of about 540° C. to about 620° C. for a period which is sufficient for the microstructure of the steel in the steel wire to transform to an essentially body centered cubic microstructure; and (8) cold drawing the steel wire to a draw ratio which is sufficient to reduce the diameter of the steel wire by about 60 to about 98% to produce said steel filament.

Claim 9

A process for manufacturing steel filament which has an outstanding combination of strength and ductility which comprises the sequential steps of (1) heating a steel wire in a first patenting step to a temperature which is within the range of about 900° C. to about 1100° C. for a period of at least about 5 seconds, wherein said steel wire consists essentially of (a) about 96.3 to about 99.15 weight percent iron, (b) about 0.6 to about 1 weight percent carbon, (c) about 0.1 to about 1.2 weight percent manganese, (d) about 0.1 to about 1 weight percent silicon, and (e) about 0.05 to about 0.5 weight percent vanadium: (2) rapidly cooling said steel wire to a temperature which is within the range of about 540° C. to about 620° C. within a period of less than about 4 seconds: (3) maintaining said steel wire at a temperature within the range of about 540° C. to about 620° C. for a period which is sufficient for the microstructure of the steel in the steel wire to transform to an essentially body centered cubic microstructure: (4) cold drawing the steel wire to a draw ratio which is sufficient to reduce the diameter of the steel wire by about 40 to about 80%: (5) heating the steel wire in a second patenting step to a temperature which is within the range of about 900° C. to about 1100° C. for a period of at least about 1 second: (6) rapidly cooling said steel wire to a temperature which is within the range of about 540° C. to about 620° C. within a period of less than about 4 seconds; (7) maintaining said steel wire at a temperature within the range of about 540° C. to about 620° C. for a period which is sufficient for the microstructure of the steel in the steel wire to transform to an essentially body centered cubic microstructure; and (8) cold drawing the steel wire to a draw ratio which is sufficient to reduce the diameter of the steel wire by about 60 to about 98% to produce said steel filament.

Claim 10

A process for manufacturing steel filament which has an outstanding combination of strength and ductility which comprises the sequential steps of (1) heating a steel wire in a first patenting step to a temperature which is within the range of about 900° C. to about 1100° C. for a period of at least about 5 seconds, wherein said steel wire consists essentially of (a) about 96.3 to about 99.15 weight percent iron, (b) about 0.6 to about 1 weight percent carbon, (c) about 0.1 to about 1.2 weight percent manganese, (d) about 0.1 to about 1 weight percent silicon, and (e) about 0.05 to about 0.5 weight percent vanadium: (2) rapidly cooling said steel wire to a temperature which is within the range of about 540° C. to about 620° C. within a period of less than about 4 seconds: (3) maintaining said steel wire at a temperature within the range of about 540° C. to about 620° C. for a period which is sufficient for the microstructure of the steel in the steel wire to transform to an essentially body centered cubic microstructure: (4) cold drawing the steel wire to a draw ratio which is sufficient to reduce the diameter of the steel wire by about 40 to about 80%: (5) heating the steel wire in a second patenting step to a temperature which is within the range of about 900° C. to about 1100° C. for a period of at least about 1 second: (6) rapidly cooling said steel wire to a temperature which is within the range of about 540° C. to about 620° C. within a period of less than about 4 seconds; (7) maintaining said steel wire at a temperature within the range of about 540° C. to about 620° C. for a period which is sufficient for the microstructure of the steel in the steel wire to transform to an essentially body centered cubic microstructure; and (8) cold drawing the steel wire to a draw ratio which is sufficient to reduce the diameter of the steel wire by about 60 to about 98% to produce said steel filament.

Claim 11

A process for manufacturing steel filament which has an outstanding combination of strength and ductility which comprises the sequential steps of (1) heating a steel wire in a first patenting step to a temperature which is within the range of about 900° C. to about 1100° C. for a period of at least about 5 seconds, wherein said steel wire consists essentially of (a) about 95.4 to about 99.29 weight percent iron, (b) about 0.4 to about 1 weight percent carbon, (c) about 0.1 to about 1.2 weight percent manganese, (d) about 0.1 to about 1 weight percent silicon, (e) about 0.1 to about 0.8 weight percent chromium and (f) about 0.01 to about 0.6 weight percent niobium; (2) rapidly cooling said steel wire to a temperature which is within the range of about 540° C. to about 620° C. within a period of less than about 4 seconds: (3) maintaining said steel wire at a temperature within the range of about 540° C. to about 620° C. for a period which is sufficient for the microstructure of the steel in the steel wire to transform to an essentially body centered cubic microstructure: (4) cold drawing the steel wire to a draw ratio which is sufficient to reduce the diameter of the steel wire by about 40 to about 80%: (5) heating the steel wire in a second patenting step to a temperature which is within the range of about 900° C. to about 1100° C. for a period of at least about 1 second; (6) rapidly cooling said steel wire to a temperature which is within the range of about 540° C. to about 620° C. within a period of less than about 4 seconds; (7) maintaining said steel wire at a temperature within the range of about 540° C. to about 620° C. for a period which is sufficient for the microstructure of the steel in the steel wire to transform to an essentially body centered cubic microstructure: and (8) cold drawing the steel wire to a draw ratio which is sufficient to reduce the diameter of the steel wire by about 60 to about 98% to produce said steel filament.

Claim 12

A process for manufacturing steel filament which has an outstanding combination of strength and ductility which comprises the sequential steps of (1) heating a steel wire in a first patenting step to a temperature which is within the range of about 900° C. to about 1100° C. for a period of at least about 5 seconds, wherein said steel wire consists essentially of (a) about 95.4 to about 99.29 weight percent iron, (b) about 0.4 to about 1 weight percent carbon, (c) about 0.1 to about 1.2 weight percent manganese, (d) about 0.1 to about 1 weight percent silicon, (e) about 0.1 to about 0.8 weight percent chromium and (f) about 0.01 to about 0.6 weight percent niobium; (2) rapidly cooling said steel wire to a temperature which is within the range of about 540° C. to about 620° C. within a period of less than about 4 seconds: (3) maintaining said steel wire at a temperature within the range of about 540° C. to about 620° C. for a period which is sufficient for the microstructure of the steel in the steel wire to transform to an essentially body centered cubic microstructure: (4) cold drawing the steel wire to a draw ratio which is sufficient to reduce the diameter of the steel wire by about 40 to about 80%: (5) heating the steel wire in a second patenting step to a temperature which is within the range of about 900° C. to about 1100° C. for a period of at least about 1 second; (6) rapidly cooling said steel wire to a temperature which is within the range of about 540° C. to about 620° C. within a period of less than about 4 seconds; (7) maintaining said steel wire at a temperature within the range of about 540° C. to about 620° C. for a period which is sufficient for the microstructure of the steel in the steel wire to transform to an essentially body centered cubic microstructure: and (8) cold drawing the steel wire to a draw ratio which is sufficient to reduce the diameter of the steel wire by about 60 to about 98% to produce said steel filament.

Claim 13

A process for manufacturing steel filament which has an outstanding combination of strength and ductility which comprises the sequential steps of (1) heating a steel wire in a first patenting step to a temperature which is within the range of about 900° C. to about 1100° C. for a period of at least about 5 seconds, wherein said steel wire consists essentially of (a) about 94.94 to about 98.99 weight percent iron, (b) about 0.6 to about 1 weight percent carbon, (c) about 0.1 to about 1.2 weight percent manganese, (d) about 0.1 to about 1 weight percent silicon, (e) about 0.1 to about 0.8 weight percent chromium, (f) about 0.05 to about 0.5 weight percent cobalt, (g) about 0.05 to 0.5 weight percent vanadium, and (h) about 0.01 to 0.06 weight percent niobium: (2) rapidly cooling said steel wire to a temperature which is within the range of about 540° C. to about 620° C. within a period of less than about 4 seconds; (3) maintaining said steel wire at a temperature within the range of about 540° C. to about 620° C. for a period which is sufficient for the microstructure of the steel in the steel wire to transform to an essentially body centered cubic microstructure: (4) cold drawing the steel wire to a draw ratio which is sufficient to reduce the diameter of the steel wire by about 40 to about 80%; (5) heating the steel wire in a second patenting step to a temperature which is within the range of about 900° C. to about 1100° C. for a period of at least about 1 second; (6) rapidly cooling said steel wire to a temperature which is within the range of about 540° C. to about 620° C. within a period of less than about 4 seconds; (7) maintaining said steel wire at a temperature within the range of about 540° C. to about 620° C. for a period which is sufficient for the microstructure of the steel in the steel wire to transform to an essentially body centered cubic microstructure; and (8) cold drawing the steel wire to a draw ratio which is sufficient to reduce the diameter of the steel wire by about 60 to about 98% to produce said steel filament.

Claim 14

A process for manufacturing steel filament which has an outstanding combination of strength and ductility which comprises the sequential steps of (1) heating a steel wire in a first patenting step to a temperature which is within the range of about 900° C. to about 1100° C. for a period of at least about 5 seconds, wherein said steel wire consists essentially of (a) about 94.94 to about 98.99 weight percent iron, (b) about 0.6 to about 1 weight percent carbon, (c) about 0.1 to about 1.2 weight percent manganese, (d) about 0.1 to about 1 weight percent silicon, (e) about 0.1 to about 0.8 weight percent chromium, (f) about 0.05 to about 0.5 weight percent cobalt, (g) about 0.05 to 0.5 weight percent vanadium, and (h) about 0.01 to 0.06 weight percent niobium: (2) rapidly cooling said steel wire to a temperature which is within the range of about 540° C. to about 620° C. within a period of less than about 4 seconds; (3) maintaining said steel wire at a temperature within the range of about 540° C. to about 620° C. for a period which is sufficient for the microstructure of the steel in the steel wire to transform to an essentially body centered cubic microstructure: (4) cold drawing the steel wire to a draw ratio which is sufficient to reduce the diameter of the steel wire by about 40 to about 80%; (5) heating the steel wire in a second patenting step to a temperature which is within the range of about 900° C. to about 1100° C. for a period of at least about 1 second; (6) rapidly cooling said steel wire to a temperature which is within the range of about 540° C. to about 620° C. within a period of less than about 4 seconds; (7) maintaining said steel wire at a temperature within the range of about 540° C. to about 620° C. for a period which is sufficient for the microstructure of the steel in the steel wire to transform to an essentially body centered cubic microstructure; and (8) cold drawing the steel wire to a draw ratio which is sufficient to reduce the diameter of the steel wire by about 60 to about 98% to produce said steel filament.

Claim 15

A process for manufacturing steel filament which has an outstanding combination of strength and ductility which comprises the sequential steps of (1) heating a steel wire in a first patenting step to a temperature which is within the range of about 900° C. to about 1100° C. for a period of at least about 5 seconds, wherein said steel wire consists essentially of (a) about 94 to about 99.29 weight percent iron, (b) about 0.4 to about 1 weight percent carbon, (c) about 0.1 to about 1.2 weight percent manganese, (d) about 0.1 to about 1 weight percent silicon, (e) about 0.05 to about 0.5 weight percent vanadium, (f) about 0.05 to about 0.5 weight percent molybdenum, and (g) about 0.01 to about 0.06 weight percent niobium: (2) rapidly cooling said steel wire to a temperature which is within the range of about 540° C. to about 620° C. within a period of less than about 4 seconds: (3) maintaining said steel wire at a temperature within the range of about 540° C. to about 620° C. for a period which is sufficient for the microstructure of the steel in the steel wire to transform to an essentially body centered cubic microstructure: (4) cold drawing the steel wire to a draw ratio which is sufficient to reduce the diameter of the steel wire by about 40 to about 80%; (5) heating the steel wire in a second patenting step to a temperature which is within the range of about 900° C. to about 1100° C. for a period of at least about 1 second; (6) rapidly cooling said steel wire to a temperature which is within the range of about 540° C. to about 620° C. within a period of less than about 4 seconds; (7) maintaining said steel wire at a temperature within the range of about 540° C. to about 620° C. for a period which is sufficient for the microstructure of the steel in the steel wire to transform to an essentially body centered cubic microstructure; and (8) cold drawing the steel wire to a draw ratio which is sufficient to reduce the diameter of the steel wire by about 60 to about 98% to produce said steel filament.

Claim 16

A process for manufacturing steel filament which has an outstanding combination of strength and ductility which comprises the sequential steps of (1) heating a steel wire in a first patenting step to a temperature which is within the range of about 900° C. to about 1100° C. for a period of at least about 5 seconds, wherein said steel wire consists essentially of (a) about 94 to about 99.29 weight percent iron, (b) about 0.4 to about 1 weight percent carbon, (c) about 0.1 to about 1.2 weight percent manganese, (d) about 0.1 to about 1 weight percent silicon, (e) about 0.05 to about 0.5 weight percent vanadium, (f) about 0.05 to about 0.5 weight percent molybdenum, and (g) about 0.01 to about 0.06 weight percent niobium: (2) rapidly cooling said steel wire to a temperature which is within the range of about 540° C. to about 620° C. within a period of less than about 4 seconds: (3) maintaining said steel wire at a temperature within the range of about 540° C. to about 620° C. for a period which is sufficient for the microstructure of the steel in the steel wire to transform to an essentially body centered cubic microstructure: (4) cold drawing the steel wire to a draw ratio which is sufficient to reduce the diameter of the steel wire by about 40 to about 80%; (5) heating the steel wire in a second patenting step to a temperature which is within the range of about 900° C. to about 1100° C. for a period of at least about 1 second; (6) rapidly cooling said steel wire to a temperature which is within the range of about 540° C. to about 620° C. within a period of less than about 4 seconds; (7) maintaining said steel wire at a temperature within the range of about 540° C. to about 620° C. for a period which is sufficient for the microstructure of the steel in the steel wire to transform to an essentially body centered cubic microstructure; and (8) cold drawing the steel wire to a draw ratio which is sufficient to reduce the diameter of the steel wire by about 60 to about 98% to produce said steel filament.

Claim 17

A process for manufacturing steel filament which has an outstanding combination of strength and ductility which comprises the sequential steps of (1) heating a steel wire in a first patenting step to a temperature which is within the range of about 900° C. to about 1100° C. for a period of at least about 5 seconds, wherein said steel wire consists essentially of (a) about 95.74 to about 99.09 weight percent iron, (b) about 0.6 to about 1 weight percent carbon, (c) about 0.1 to about 1.2 weight percent manganese, (d) about 0.1 to about 1 weight percent silicon, (e) about 0.01 to about 0.06 weight percent niobium, (f) about 0.05 to about 0.5 weight percent molybdenum, and (g) about 0.05 to about 0.5 weight percent cobalt: (2) rapidly cooling said steel wire to a temperature which is within the range of about 540° C. to about 620° C. within a period of less than about 4 seconds; (3) maintaining said steel wire at a temperature within the range of about 540° C. to about 620° C. for a period which is sufficient for the microstructure of the steel in the steel wire to transform to an essentially body centered cubic microstructure; (4) cold drawing the steel wire to a draw ratio which is sufficient to reduce the diameter of the steel wire by about 40 to about 80%: (5) heating the steel wire in a second patenting step to a temperature which is within the range of about 900° C. to about 1100° C. for a period of at least about 1 second; (6) rapidly cooling said steel wire to a temperature which is within the range of about 540° C. to about 620° C. within a period of less than about 4 seconds: (7) maintaining said steel wire at a temperature within the range of about 540° C. to about 620° C. for a period which is sufficient for the microstructure of the steel in the steel wire to transform to an essentially body centered cubic microstructure; and (8) cold drawing the steel wire to a draw ratio which is sufficient to reduce the diameter of the steel wire by about 60 to about 98% to produce said steel filament.

Claim 18

A process for manufacturing steel filament which has an outstanding combination of strength and ductility which comprises the sequential steps of (1) heating a steel wire in a first patenting step to a temperature which is within the range of about 900° C. to about 1100° C. for a period of at least about 5 seconds, wherein said steel wire consists essentially of (a) about 95.74 to about 99.09 weight percent iron, (b) about 0.6 to about 1 weight percent carbon, (c) about 0.1 to about 1.2 weight percent manganese, (d) about 0.1 to about 1 weight percent silicon, (e) about 0.01 to about 0.06 weight percent niobium, (f) about 0.05 to about 0.5 weight percent molybdenum, and (g) about 0.05 to about 0.5 weight percent cobalt: (2) rapidly cooling said steel wire to a temperature which is within the range of about 540° C. to about 620° C. within a period of less than about 4 seconds; (3) maintaining said steel wire at a temperature within the range of about 540° C. to about 620° C. for a period which is sufficient for the microstructure of the steel in the steel wire to transform to an essentially body centered cubic microstructure; (4) cold drawing the steel wire to a draw ratio which is sufficient to reduce the diameter of the steel wire by about 40 to about 80%: (5) heating the steel wire in a second patenting step to a temperature which is within the range of about 900° C. to about 1100° C. for a period of at least about 1 second; (6) rapidly cooling said steel wire to a temperature which is within the range of about 540° C. to about 620° C. within a period of less than about 4 seconds: (7) maintaining said steel wire at a temperature within the range of about 540° C. to about 620° C. for a period which is sufficient for the microstructure of the steel in the steel wire to transform to an essentially body centered cubic microstructure; and (8) cold drawing the steel wire to a draw ratio which is sufficient to reduce the diameter of the steel wire by about 60 to about 98% to produce said steel filament.

Claim 19

A process as specified in claim 1 wherein said steel wire consists essentially of (a) about 97.5 to about 98.5 weight percent iron, (b) about 0.8 to about 0.9 weight percent carbon, (c) about 0.3 to about 0.7 weight percent silicon, (d) about 0.2 to about 0.5 weight percent manganese, and (e) about 0.2 to about 0.4 weight percent chromium.

Claim 20

A process as specified in claim 2 wherein said steel wire consists essentially of (a) about 97.4 to about 98.5 weight percent iron, (b) about 0.7 to about 0.8 weight percent carbon, (c) about 0.4 to about 0.8 weight percent manganese, (d) about 0.1 to about 0.3 weight percent silicon, (e) about 0.2 to about 0.5 weight percent chromium (f) about 0.1 to about 0.2 weight percent cobalt.

Claim 21

A process as specified in claim 3 wherein said steel wire consists essentially of (a) about 97.6 to about 98.5 weight percent iron, (b) about 0.6 to about 0.7 weight percent carbon, (c) about 0.6 to about 1.0 weight percent manganese, (d) about 0.1 to about 0.3 weight percent silicon, (e) about 0.1 to about 0.2 weight percent molybdenum and (f) about 0.1 to about 0.2 weight percent cobalt.

Claim 22

A process as specified in claim 4 wherein said steel wire consists essentially of (a) about 97.66 to about 98.58 weight percent iron, (b) about 0.7 to about 0.8 weight percent carbon, (c) about 0.4 to about 0.8 weight percent manganese, (d) about 0.1 to about 0.3 weight percent silicon, (e) about 0.02 to about 0.04 weight percent niobium (f) about 0.1 to about 0.2 weight percent molybdenum, and (g) about 0.1 to about 0.2 weight percent cobalt.

Claim 23

A process as specified in claim 5 wherein said steel wire consists essentially of (a) about 97.9 to about 98.7 weight percent iron, (b) about 0.7 to about 0.8 weight percent carbon, (c) about 0.4 to about 0.8 weight percent manganese, (d) about 0.1 to about 0.3 weight percent silicon, and (e) about 0.1 to about 0.2 weight percent vanadium.

Claim 24

A process as specified in claim 6 wherein said steel wire consists essentially of (a) about 97.66 to about 98.68 weight percent iron, (b) about 0.6 to about 0.7 weight percent carbon, (c) about 0.4 to about 0.8 weight percent manganese, (d) about 0.1 to about 0.3 weight percent silicon, (e) about 0.2 to about 0.5 weight percent chromium and (f) about 0.02 to about 0.04 weight percent niobium.

Claim 25

A process as specified in claim 7 wherein said steel wire consists essentially of (a) about 97.16 to about 98.38 weight percent iron, (b) about 0.7 to about 0.8 weight percent carbon, (c) about 0 4 to about 0.8 weight percent manganese, (d) about 0.1 to about 0.3 weight percent silicon, (e) about 0.2 to about 0.5 weight percent chromium, (f) about 0.1 to about 0.2 weight percent cobalt, (g) about 0.1 to 0.2 weight percent vanadium, and (h) about 0.02 to 0.04 weight percent niobium.

Claim 26

A process as specified in claim 8 wherein said steel wire consists essentially of (a) about 97 76 to about 98.68 weight percent iron, (b) about 0.6 to about 0.7 weight percent carbon, (c) about 0.4 to about 0.8 weight percent manganese, (d) about 0.1 to about 0.3 weight percent silicon, (e) about 0.1 to about 0.2 weight percent vanadium, (f) about 0.1 to about 0.2 weight percent molybdenum, and (g) about 0.02 to about 0.04 weight percent niobium.

Claim 27

A process as specified in claim 9 wherein said steel wire consists essentially of (a) about 97.26 to about 98.38 weight percent iron, (b) about 0.7 to about 0.8 weight percent carbon, (c) about 0.4 to about 0.8 weight percent manganese, (d) about 0.3 to about 0.7 weight percent silicon, (e) about 0.02 to about 0.04 weight percent niobium, (f) about 0.1 to about 0.2 weight percent molybdenum, and (g) about 0.1 to about 0.2 weight percent cobalt.