Abstract:
PURPOSE: A method for manufacturing a high-strength deformed bar with low yield ratio is provided to form a central part as a mixing tissue of pearlite and ferrite and to secure high intensity and the low yield ratio. CONSTITUTION: A steel material is heated at a temperature range of 1000~1250°C. The steel material is hot-rolled under a rolling termination temperature condition. The steel material is water-cooled under an operation condition within a coolant bath. A superficial part is recuperated to the temperature range of AC1+10°C~AC1+80°C. The steel material is made of C(Carbon) 0.1~0.4wt.%, Si(Silicon) 0.1~0.6wt.%, Mn(Manganese) 0.4~1.5wt.%, P(Phosphorus) less than 0.03wt.%, S(Sulfur) less than 0.03wt.%, Cu(Copper) less than 0.3wt.%, V(Vanadium) less than 0.15wt.%, residual Fe(Iron) and inevitable impurities.
Abstract:
본 발명은 표층부에는 연질상인 페라이트와 경한 상인 마르텐사이트의 혼합조직이고, 중심부에는 페라이트와 퍼얼라이트의 혼합조직을 형성시킴으로써 고강도이면서도 낮은 항복비를 가지는 고강도 저항복비 철근의 제조방법에 관한 것으로, 본 발명의 바람직한 실시예에 따른 고강도 저항복비 철근의 제조방법은 중량%로 C:0.1~0.4%, Si: 0.1~0.6, Mn: 0.4~1.5%, P: 0.03%이하, S: 0.03%이하, Cu: 0.3%이하, V: 0.15%이하 및 나머지는 Fe 및 기타 불가피하게 함유되는 불순물로 구성되는 강재를 1000℃~1250℃의 온도범위로 가열하고, 철근압연공정에서 소정의 압연종료 온도조건으로 열간압연한 후, 소정의 냉각조 내에서 소정의 조업조건으로 수냉하여, 표층부를 A C1 +10℃~A C1 +80℃의 온도범위로 복열시켜 이루어진다. 고강도, 저항복비, 철근
Abstract:
An iron rod packing apparatus, a method for packing iron rod, and a method for loading iron rod are provided, which prevent corrosion of the iron rod and effectively keeps the iron rod. An iron rod packing apparatus comprises: a band member(15) which binds a plurality of iron rods; an anti-rust sheet which wraps the band member and iron rod; and a belt sling(41) which comprises the belt part(42) and annular part(43). Each belt part is connected to the location more than two locations of the anti-rust sheet about one or more anti-rust sheet package bundles. One or more loops are equipped in each belt part. One or more buffer members are equipped in the belt part.