CORROSION-RESISTANT STEEL MATERIAL FOR BULK CARRIER AND HOLD OF BULK CARRIER

摘要

PURPOSE: A corrosion resistant steel material for a bulker and a hold of the bulker are provided to secure an excellent long-term corrosion resistance under a strict corrosive environment due to a bulk cargo including sulfur content, thereby properly using the steel material as a structural member of the bulker. CONSTITUTION: A corrosion resistant steel material for a bulker comprises 0.04 to 0.30 mass% of C, 0.28 to 0.60 mass% of Si, 0.1 to 2.0 mass% of Mn, 0.010 to 0.040 mass% of P, 0.003 to 0.025 mass% of S, 0.010 to 0.10 mass% of Al, 0.10 to 1.0 mass% of Cu, less than 0.010 mass%(except 0 mass%) of Ni, 0.0030 to 0.010 mass% of N, remnant Fe, and other inevitable impurities. The steel material has more than 0.10 of CP1 determined by an equation(1), and at the same time 0.80 to 7.00 of CP2 determined by an equation(2). The steel material has an excellent corrosion resistance under a strict corrosive environment due to a bulk cargo including a sulfur content. The equations(1,2) are as follows: Equation(1): CP1= Si +2 Cu -5 Ni. Equation(2): CP2= (P / 4 + S) / N. The steel material includes at least one kind selected from a group of 0.01 to 0.3 wt% of C, 0.005 to 0.3 wt% of Sn, and 0.005 to 0.3 wt% of Sb, and at least one kind selected from a group of 0.0003 to 0.005 wt% of Ca, 0.001 to 0.05 wt% of Ti, 0.001 to 0.05 wt% of V, 0.001 to 0.05 wt% of Nb, and 0.0003 to 0.005 wt% of B. [Reference numerals] (AA) Thickness 5mm