Steel wire with excellent corrosion resistance and appearance after processing

Abstract

To provide a steel wire rod having a lubricating coating, which can achieve both corrosion resistance such as long-term rust prevention property, and excellent appearance after heading. The steel wire rod of the present disclosure includes a lubricating coating on a surface thereof, wherein the lubricating coating includes silicon (A), tungsten (B) and an alkali metal salt of fatty acid (C), a dry mass ratio of (B)/(A) is in a range of 1.3 to 18 and a dry mass ratio of (C)/{(A)+(B)} is in a range of 0.14 to 2.0, and the lubricating coating contains no phosphorus.

1 : A steel wire rod comprising a lubricating coating on a surface thereof, wherein the lubricating coating comprises:
 (A) silicon (A);   (B) tungsten (B); and   (C) an alkali metal salt of fatty acid (C),   
       wherein:
 a dry mass ratio of (B)/(A) ranges from 1.3 to 18; 
 a dry mass ratio of (C)/{(A)+(B)} ranges from 0.14 to 2.0; and 
 the lubricating coating contains no phosphorus. 
 
     
     
         2 : The steel wire rod according to  claim 1 , wherein
 the silicon (A) is derived from a water-soluble silicate; and   the tungsten (B) is derived from a water-soluble tungstate.   
     
     
         3 : The steel wire rod according to  claim 1 , wherein:
 the silicon (A) is derived from at least one selected from the group consisting of lithium silicate, sodium silicate and potassium silicate; and   the tungsten (B) is derived from at least one selected from the group consisting of lithium tungstate, sodium tungstate, potassium tungstate and ammonium tungstate.   
     
     
         4 : The steel wire rod according to  claim 1 , wherein;
 the lubricating coating further comprises:
 (D) a lubricant (D) other than the alkali metal salt of fatty acid (C); and 
   a dry mass ratio of {(C)+(D)}/{(A)+(B)} ranges from 0.14 to 2.0.   
     
     
         5 : The steel wire rod according to  claim 4 , wherein the lubricant (D) is at least one selected from the group consisting of a wax, a polytetra fluoroethylene, a fatty acid metal soap, a fatty acid amide, molybdenum disulfide, tungsten disulfide, graphite, and melamine cyanurate. 
     
     
         6 : The steel wire rod according to  claim 1 , wherein
 the lubricating coating further comprises:
 (E) a resin (E); and 
   a dry mass ratio of (E)/{(A)+(B)} exceeds 0 and is 1.4 or less.   
     
     
         7 : The steel wire rod according to  claim 6 , wherein the resin (E) is at least one selected from the group consisting of a vinyl resin, an acrylic resin, an epoxy resin, a urethane resin, a phenol resin, a cellulose derivative, a polymaleic acid, and a polyester resin. 
     
     
         8 : The steel wire rod according to  claim 1 , wherein a mass of a coating per unit area of the lubricating coating ranges from 1.0 to 20 g/m 2 .