| 摘要 |
<p>PURPOSE:To provide the suitable mechanical properties as bar steel for PC and to produce the bar steel having excellent linearity by executing heat- treatment under the prescribed condition after making the steel having the specific composition in the range of low C content, which is possible to quench, a deformed bar steel having large diameter. CONSTITUTION:At the time of giving the deformed bar steel having large diameter forming discontinuous screw thread on the peripheral face by hot rolling, high strength, the steel material containing by wt% of <=0.6 C, 0.15-2.00 Si, 0.6-2.00 Mn or further adding <=0.6 Cr is used. This steel material is hot rolled to obtain the deformed bar steel having large diameter as showing in the figure, and the bar steel is obtd. by cutting this to regular size. While continuously sending this bar steel with surface as rolled on the heat-treatment line, the induction heating by the suitable frequency and powder in accordance with the diameter of bar steel is executed. Next, under the restraining condition by cooling fluid injected by a jacket, the bar steel is rapidly cooled to quench and further tempered.</p> |
