| 摘要 |
A bolting bar material consists in weight ratio of 0.05 DIFFERENCE 0.2% of C, 0.05 DIFFERENCE 0.8% of Si, 0.8 DIFFERENCE 2% of Mn, not more than 0.035% of P, not more than 0.030% of S, 0.005 DIFFERENCE 0.05% of Nb, 0.01 DIFFERENCE 0.05% of Al, 0.005 DIFFERENCE 0.025% of N, 0.05 DIFFERENCE 0.35% in total of at least one element selected from not more than 0.25% of V, not more than 0.25% of Ti and not more than 0.25% of Zr, and if necessary, 0.05 DIFFERENCE 1.5% in total of at least one element selected from 0.05 DIFFERENCE 0.5% of Ni, 0.05 DIFFERENCE 0.5% of Cr and 0.05 DIFFERENCE 0.5% of Mo, and the balance of Fe. In the production of the bolting bar material, the steel having the above composition is heated to 1000 DEG DIFFERENCE 1100 DEG C., rolled at a finish rolling temperature of 750 DEG DIFFERENCE 950 DEG C. and cooled at a rate of 5 DEG DIFFERENCE 50 DEG C./sec on average.
|
