| 摘要 |
<p>PURPOSE: V-free microalloyed steel having equal quality to tempered carbon steel and a method for producing the same are provided to obtain microalloyed steel with high yield ratio without the addition of V and a tempering process. CONSTITUTION: A method of producing V-free microalloyed steel having equal quality to tempered carbon steel is as follows. A steel material is heated to 1200~1300°C for minute precipitation of stable carbon nitride. The heated steel material is finished through hot rolling at a temperature of 900~1000°C. The steel material comprises carbon 0.20~0.60 weight%, silicon 0.30~0.80 weight%, manganese 0.50~1.00 weight%, sulfur 0.020~0.050 weight%, chrome 0.10~0.50 weight%, aluminum 0.020~0.050 weight%, nitrogen 80~180 ppm, and iron and inevitable impurities of the rest amount.</p> |
