High tensile strength steel wire

Patent metadata

Field	Value
Publication number	US-2016237518-A1
Application number	US-201415027856-A
Country	US
Kind code	A1
Filing date	Sep 30, 2014
Priority date	Oct 11, 2013
Publication date	Aug 18, 2016
Grant date	—

Abstract

A high tensile strength steel wire having as steel composition: a carbon content ranging from 0.20 weight percent to 1.00 weight percent, e.g. from 0.3 weight percent to 0.85 weight percent, e.g. from 0.4 weight percent to 0.7 weight percent, e.g. from 0.5 weight percent to 0.6 weight percent, a silicon content ranging from 0.05 weight percent to 2.0 weight percent, e.g. from 0.2 weight percent to 1.8 weight percent, e.g. from 1.2 weight percent to 1.6 weight percent, a manganese content ranging from 0.40 weight percent to 1.0 weight percent, e.g. from 0.5 weight percent to 0.9 weight percent, a chromium content ranging from 0.0 weight percent to 1.0 weight percent, e.g. from 0.5 weight percent to 0.8 weight percent, a sulfur and phosphor content being individually limited to 0.05 weight percent, e.g. limited to 0.025 weight percent, contents of nickel, vanadium, aluminum, copper or other micro-alloying elements all being individually limited to 0.5 weight percent, e.g. limited to 0.2 weight percent, e.g. limited to 0.08 weight percent, the remainder being iron, said steel wire having martensitic structure, wherein at least 10 volume percent of martensite are oriented.

First claim

1 . A high tensile strength steel wire having as steel composition:
a carbon content ranging from 0.20 weight percent to 1.00 weight percent, e.g. from 0.3 weight percent to 0.85 weight percent, e.g. from 0.4 weight percent to 0.7 weight percent, e.g. from 0.5 weight percent to 0.6 weight percent, a silicon content ranging from 0.05 weight percent to 2.0 weight percent, e.g. from 0.2 weight percent to 1.8 weight percent, e.g. from 1.2 weight percent to 1.6 weight percent, a manganese content ranging from 0.40 weight percent to 1.0 weight percent, e.g. from 0.5 weight percent to 0.9 weight percent, a chromium content ranging from 0.0 weight percent to 1.0 weight percent, e.g. from 0.5 weight percent to 0.8 weight percent, a sulfur and phosphor content being individually limited to 0.05 weight percent, e.g. limited to 0.025 weight percent, contents of nickel, vanadium, aluminum, copper or other micro-alloying elements all being individually limited to 0.5 weight percent, e.g. limited to 0.2 weight percent, e.g. limited to 0.08 weight percent,
the remainder being iron,
said steel wire having martensitic structure,
wherein at least 10 volume percent of martensite are oriented.

2 . A high tensile strength steel wire according to claim 1 , wherein at least 20 volume percent of martensite are oriented.

3 . A high tensile strength steel wire according to claim 1 , wherein at least 40 volume percent of martensite are oriented.

4 . A high tensile strength steel wire according to claim 1 , wherein said steel wire has a yield strength Rp0.2 which is at least 80 percent of the tensile strength Rm.

5 . A high tensile strength steel wire according to claim 1 , wherein said steel wire has a corrosion resistance coating.

6 . A high tensile strength steel wire according to claim 5 , wherein said corrosion resistance coating is selected from any one of zinc, nickel, silver and copper, or their alloys.

7 . A high tensile strength steel wire according to claim 1 , said steel wire being in a cold-drawn state and having a round cross-section.

8 . A high tensile strength steel wire according to claim 1 , wherein said steel wire has a tensile strength R m of at least 2000 MPa for wire diameter above 5.0 mm, at least 2100 MPa for wire diameter above 3.0 mm and at least 2200 MPa for wire diameters above 0.5 mm.

9 . A high tensile strength steel wire according to claim 1 , wherein said steel wire has a reduction in area after fracture of at least 45%.

10 . A high tensile strength steel wire according to claim 1 , wherein said steel wire has a reduction in area after fracture of at least 50%.

11 . Use of a high tensile strength steel wire according to claim 1 as a spring wire or an element for producing a rope.

12 . A process of manufacturing a high tensile strength steel wire,
said steel wire having as steel composition:
a carbon content ranging from 0.20 weight percent to 1.00 weight percent, e.g. from 0.3 weight percent to 0.85 weight percent, e.g. from 0.4 weight percent to 0.7 weight percent, e.g. from 0.5 weight percent to 0.6 weight percent,
a silicon content ranging from 0.05 weight percent to 2.0 weight percent, e.g. from 0.2 weight percent to 1.8 weight percent, e.g. from 1.2 weight percent to 1.6 weight percent,
a manganese content ranging from 0.40 weight percent to 1.0 weight percent, e.g. from 0.5 weight percent to 0.9 weight percent,
a chromium content ranging from 0.0 weight percent to 1.0 weight percent, e.g. from 0.5 weight percent to 0.8 weight percent,
a sulfur and phosphor content being individually limited to 0.05 weight percent, e.g. limited to 0.025 weight percent,
contents of nickel, vanadium, aluminum, copper or other micro-alloying elements all being individually limited to 0.5 weight percent, e.g. limited to 0.2 weight percent, e.g. limited to 0.08 weight percent,
the remainder being iron, said steel having martensitic structure, wherein at least 10 volume percent of martensite are oriented. said process comprising the following steps in order: a) austenitizing a steel wire rod or steel wire above Ac3 temperature during a period less than 120 seconds, b) quenching said austenitized steel wire rod or steel wire below 100° C. during a period less than 60 seconds, c) tempering said quenched steel wire rod or steel wire between 320° C. and 500° C. during a period ranging from 10 seconds to 600 seconds, d) work hardening said quenched and tempered steel wire rod or steel wire.

13 . A process of manufacturing a high tensile strength steel wire according to claim 12 , wherein said process is further followed by a step of:
e) aging said work hardened steel wire at a temperature between 100° C. and 250° C.

14 . A process of manufacturing a high tensile strength steel wire according to claim 12 , wherein said work hardening occurs at a temperature below 700° C.

15 . A process of manufacturing a high tensile strength steel wire according to claim 12 , wherein said work hardening is cold drawing.

Assignees

• Bekaert Sa Nv

Inventors

• Mesplont Christophe

Classifications

• C21D8/06

  during manufacturing of rods or wires · CPC title

• C22C38/60

  containing lead, selenium, tellurium, or antimony, or more than 0.04% by weight of sulfur · CPC title

• C21D9/52

  for wires; for strips {; for rods of unlimited length} · CPC title

• C22C38/00

  Ferrous alloys, e.g. steel alloys (cast-iron alloys C22C37/00) · CPC title

• C21D9/02 Primary

  for springs · CPC title