Economical low-segregation-degree high-homogeneity 355MPa-grade steel plate for hull structure and preparation method thereof

The invention relates to an economical low-segregation-degree high-homogeneity 355MPa-grade steel plate for a hull structure and a preparation method of the economical low-segregation-degree high-homogeneity 355MPa-grade steel plate. The steel plate comprises the following chemical components in percentage by weight: 0.12-0.16% of C, 0.20-0.40% of Si, 0.80-1.20% of Mn, less than or equal to 0.010% of P, less than or equal to 0.0050% of S, 0.020-0.030% of Al, 0.010-0.020% of Ti and the balance of Fe and inevitable impurity elements. The carbon equivalent CEV is smaller than or equal to 0.34%, and the manufacturing technological process of the steel plate is a BOF converter-gt; lF refining-gt; performing RH vacuum degassing-gt; continuous casting-gt; heating-gt; and rolling. The prepared steel plate fully exerts the characteristics of low manufacturing cost, short production process and excellent plate shape under the conditions of high strength, high toughness and easy welding. The problems that the thin steel