HOT ROLLING STEEL PLATE WITH HIGH STRENGTH AND HIGH TOUGHNESS FOR A STEEL PILE AND METHOD OF MANUFACTURING THE SAME CAPABLE OF CONTROLLING PROCESS CONDITIONS INCLUDING ROUGH ROLLING

摘要

PURPOSE: A hot rolling steel plate with high strength and high toughness for a steel pile and a method of manufacturing the same are provided to ensure excellent toughness since fine crystal grain is maintained at a heat affected zone in welding by effect of curbing the growth of crystal grain by precipitate.;CONSTITUTION: A hot rolling steel plate with high strength and high toughness for a steel pile comprises C of 0.01 ~ 0.1 weight%, Si of 0.1 ~ 0.3 weight%, Mn of 1.0 ~ 1.5 weight%, P of 0.02 weight% or less, S of 0.005weight% or less, and Al of 0.05 weight% or less, and satisfies the formulas 1 and 2 below. The steel plate further comprises Fe and inevitable impurities. A fine structure is a complex structure comprising ferrite and pearlite. Formula 1. Formula 2. At the equations 1 and 2, [Nb], [V], [C], [Mn] and [Si] are the weight% of each component. Nb is added by 0.05 ~ 0.1 weight%. V is added by 0.05 ~ 0.1 weight%.;COPYRIGHT KIPO 2012