| 摘要 |
<p>PURPOSE:To regulate the tensile strength of a steel wire to a target value by a method in which the deviation of tensile strength due to a deviation of carbon equivalent from a target carbon equivalent value is controlled by regulation of cooling conditions when a high-carbon steel wire is, after being hot-rolled, directly heat-treated by using its sensible heat. CONSTITUTION:A piano wire or hard steel wire, containing 0.39-0.86% C, is hot-rolled and then directly heat-treated by using its sensible heat. In this case, the steel wire is refined while regulating its chemical composition to the target carbon equivalent previously set up on the basis of the chemical composition of the steel wire to be manufactured. And, the difference in tensile strength, caused by the difference between calculated carbon equivalent based on the chemical composition of the steel wire manufactured and the target carbon equivalent is countervailed by regulation of cooling condition immediately after the rolling of the steel wire. In short, the deviation of the target tensile strength due to the deviation of the carbon equivalent is controlled by regulation of cooling condition for the steel wire and high-carbon steel wire having a target characteristic for every lot can be exactly manufactured by a direct-heating treatment method.</p> |
