Spring steel wire rod excellent in pickling performance

Abstract

A spring steel wire rod according to the present invention is a spring steel wire rod wherein: the spring steel wire rod contains C: 0.35% to 0.7% (by mass, the same is hereunder applied), Si: 1.5% to 2.50%, Mn: 0.05% to 1.0%, Cr: 0.05% to 1.9%, Cu: 0.05% to 0.7%, Ni: 0.15% to 0.8%, P: 0.02% or less (excluding 0%), S: 0.02% or less (excluding 0%); and the balance being Fe and unavoidable impurities, wherein the ratio of Si to Cu (Si/Cu) is in the range of 4 or more; and the difference between the concentration of Cu in the surface layer and the concentration of Cu in the steel is 0.50% or less and the difference between the concentration of Ni in the surface layer and the concentration of Ni in the steel is 1.00% or less. The present invention makes it possible to improve pickling performance in a spring steel wire rod containing Si abundantly and further Cr, Cu, and Ni.

1 . A spring steel wire rod comprising: 
 C: 0.35% to 0.7% (by mass, the same is hereunder applied unless otherwise specified);    Si: 1.5% to 2.50%;    Mn: 0.05% to 1.0%;    Cr: 0.05% to 1.9%;    Cu: 0.05% to 0.7%;    Ni: 0.15% to 0.8%;    P: 0.02% or less (excluding 0%); and    S: 0.02% or less (excluding 0%),    wherein the ratio of Si to Cu (Si/Cu) is in the range of 4.0 or more, and    the difference between the concentration of Cu in the surface layer and the concentration of Cu in the steel is 0.50% or less and the difference between the concentration of Ni in the surface layer and the concentration of Ni in the steel is 1.00% or less.    
   
   
       2 . The spring steel wire rod according to  claim 1 , wherein said spring steel wire rod further contains at least one element selected from among the group comprising: 
 V: 0.07% to 0.4%;    Ti: 0.01% to 0.1%; and    Nb: 0.01% to 0.1%.    
   
   
       3 . A spring fabricated from the spring steel wire rod according to  claim 1.