| 摘要 |
<p>Disclosed are steel for a crude oil tank and a manufacturing method thereof, wherein the steel can have an increased service lifetime by improving a galvanic corrosion resistance between a base material part and a welding part through an alloy element control and a process condition control. The manufacturing method of the steel according to the present invention comprises: a step (a) of reheating a slab sheet at a slab reheating temperature (SRT) of 1050 to 1200°C; a step (b) of firstly rolling the reheated sheet in an austenite recrystallization zone; a step (c) of secondly rolling the firstly rolled sheet under the condition of a finishing rolling temperature (FRT) of 800 to 850°C; and a step (d) of cooling the secondly rolled sheet to a cooling finishing temperature of 500 to 550°C, wherein the slab sheet comprises 0.03 to 0.15 wt% of C, 0.1 to 0.6 wt% of Si, 0.5 to 1.8 wt% of Mn, at most 0.02 wt% of P, at most 0.01 wt% of S, 0.1 to 1.0 wt% of Ni, 0.01 to 1.00 wt% of Mo, 0.01 to 0.10 wt% of Al, 0.1 to 0.5 wt% of Cu, 0.005 to 0.050 wt% of Ti, 0.005 to 0.050 wt% of Nb, 0.01 to 0.10 wt% of V, 0.0001 to 0.0050 wt% of B, at most 0.010 wt% of N, and remnants Fe and inevitable impurities.</p> |
