Steel Wire Having Excellent Straightness Quality and Manufacturing Method Thereof

Abstract

Provided are a steel wire having excellent straightness quality and a method of manufacturing the steel wire, wherein the steel wire includes a wire, after undergoing a drawing operation, undergoing a heating operation of performing heating in a state in which tension is applied, and undergoing a cooling operation, wherein, when winding the wire around a winding portion having a diameter greater than a diameter of the wire for a preset period of time and then measuring straightness of the wire of 400 mm, the straightness of the wire is less than or equal to 30 mm, and the method includes a wire preparation operation, a heating operation, a cooling operation, and a straightness measurement operation.

1 . A steel wire needing straightness having excellent straightness quality, the steel wire comprising:
 a wire, after undergoing a drawing operation, undergoing a heating operation of performing heating in a state in which tension is applied, and undergoing a cooling operation, wherein,   when winding the wire around a winding portion having a diameter greater than a diameter of the wire for a preset period of time and then measuring straightness of the wire of 400 mm,   the straightness of the wire is less than or equal to 30 mm.   
     
     
         2 . The steel wire of  claim 1 , wherein a heating temperature in the heating operation is about 80° C. to 220° C. 
     
     
         3 . The steel wire of  claim 2 , wherein
 the heating temperature and a heating time in the heating operation of the wire satisfy Equation A below, and   the heating temperature in the heating operation is higher than or equal to 80° C.,   wherein Equation A: T+15.67 ln(t)≥300, wherein T denotes absolute temperature K of the heating temperature, and t denotes the heating time s.   
     
     
         4 . The steel wire of  claim 3 , wherein the heating time in the heating operation is about 0.02 s to about 10 s. 
     
     
         5 . The steel wire of  claim 1 , wherein tension applied to the wire in the heating operation is about 1% to about 50% of a cutting strength. 
     
     
         6 . A method of manufacturing a steel wire needing straightness having excellent straightness quality, the method comprising:
 a wire preparation operation of preparing a wire that is drawn;   a heating operation of heating the wire in a state in which tension is applied;   a cooling operation of cooling the wire; and   a straightness measurement operation of winding the wire around a winding portion having a diameter greater than a diameter of the wire for a preset period of time and then measuring straightness of the wire, wherein,   when measuring the straightness of the wire of 400 mm in the straightness measurement operation, the straightness of the wire is less than or equal to 30 mm.   
     
     
         7 . The method of  claim 6 , wherein the wire comprises a plurality of wires, wherein the method further comprises a stranding operation of twisting and stranding the plurality of wires to each other. 
     
     
         8 . The method of  claim 6 , wherein a heating temperature in the heating operation is about 80° C. to about 220° C. 
     
     
         9 . The method of  claim 8 , wherein
 the heating temperature and a heating time in the heating operation of the wire satisfy Equation A below, and   the heating temperature in the heating operation is higher than or equal to 80° C.,   wherein Equation A: T+15.67 ln(t)≥300, wherein T denotes absolute temperature K of the heating temperature, and t denotes the heating time s.   
     
     
         10 . The method of  claim 9 , wherein the heating time in the heating operation is about 0.02 s to about 10 s. 
     
     
         11 . The method of  claim 6 , wherein tension applied to the wire in the heating operation is about 1% to about 50% of a cutting strength.