| 摘要 |
<p>The steel has a yield limit of at least 60 kp/mm2, good notch toughness at -20 degrees C and good weldability. Its compn. is 0.15-0.22% C, 0.10-0.60% Si, 0.90-1.60% Mn, 0.05-0.40% Cr, 0.05-0.40% Ni, 0.01-0.40% Cu, 0.06-0.12% V, 0.02-0.05% Nb. 0-0.10% acid soluble Al, 0.013-0.025% N, balance Fe and usual impurities, and a C equiv. following the relation C+mn/6 + (Cr+V)/5+ (Ni+Cu)/15, and depending on the dia. of the rolled bar across section lies pref. between 0.38-0.50. The alloying elements are chosen in amts. so that after the rod is cooled in air from the rolling temp., the structure of the steel is fine-grained ferrite and pearlite. Used for concrete reinforcing rods or bars with a dia. of up to about 20 mm.</p> |
