STEEL WIRE ROD HAVING COATING FILM THAT HAS EXCELLENT CORROSION RESISTANCE AND WORKABILITY AND METHOD FOR PRODUCING SAME

摘要

The present invention provides: a steel wire rod having a lubricating coating film, which is capable of achieving a good balance between workability such as wire drawability, spiking properties and ball ironing properties and corrosion resistance such as long-term rust prevention properties; and a method for producing this steel wire rod. A steel wire rod having a coating film that does not contain phosphorus, which is characterized in that the coating film is composed of, sequentially from the steel wire rod side, a lower coating film that is formed of a zirconium oxide and/or a zirconium hydroxide and has a film thickness of 1-200 nm and an upper coating film that contains silicon and tungsten so that the tungsten/silicon mass ratio is within the range of 1.3-18. A method for producing this steel wire rod, which is characterized in that the lower coating film is formed by bringing an aqueous chemical conversion liquid into contact with the surface of the steel wire rod, said chemical conversion liquid having a pH within the range of 2.5-5.0 and being obtained by dissolving a water-soluble zirconium compound.