Heat-treated steel wire having excellent bendability

Abstract

A heat-treated steel wire having excellent bendability is provided. The heat-treated steel wire includes, in % by mass: C: 0.5 to 0.8%, Si: 1.5 to 2.5%, Mn: 0.5 to 1.5%, P: more than 0% to 0.02%, S: more than 0% to 0.02%, Cr: 0.3 to less than 0.7%, V: 0.05 to 0.5%, Al: more than 0% to 0.01%, N: more than 0% to 0.007%, and O: more than 0% to 0.004%, and iron. When electrolytic extraction residue analysis is performed using a 1.0 μm filter and a 0.4 μm filter, a ratio of [amount of Cr-based carbides in a 1.0 μm filter residue/amount of an electrolyte] is 1.0% or more and 2.80% or less. When residue analysis of the filtrate obtained by the 1.0 μm filter is performed, a ratio of [amount of Cr based carbides in a 0.4 μm filter residue/amount of an electrolyte] is 0.10% or less.

1 . A heat-treated steel wire, comprising, in % by mass:
 C: 0.5 to 0.8%,   Si: 1.5 to 2.5%,   Mn: 0.5 to 1.5%,   P: more than 0% and 0.02% or less,   S: more than 0% and 0.02% or less,   Cr: 0.3 to less than 0.7%,   V: 0.05 to 0.5%,   Al: more than 0% and 0.01% or less,   N: more than 0% and 0.007% or less,   O: more than 0% and 0.004% or less, and   iron,   wherein   when electrolytic extraction residue analysis is performed using a 1.0 μm filter and a 0.4 μm filter, a ratio of [amount of Cr based carbides in a 1.0 μm filter residue/amount of an electrolyte] is 1.0% or more and 2.80% or less, and   when residue analysis of a filtrate obtained by the 1.0 μm filter is performed, a ratio of [amount of Cr based carbides in a 0.4 μm filter residue/amount of an electrolyte] is 0.10% or less.   
     
     
         2 . The heat-treated steel wire according to  claim 1 , further comprising, in % by mass, at least one of:
 (a) Ni: more than 0% and 0.3% or less, and   (b) B: more than 0% and 0.01% or less.   
     
     
         3 . A spring, obtained by a method comprising: manufacturing the spring from the heat-treated steel wire according to  claim 1 . 
     
     
         4 . A spring, obtained by a method comprising: manufacturing the spring from the heat-treated steel wire according to  claim 2 .