Development of Thick Steel Plates for Shipbuilding Having High Strength and Good Weldability

摘要

Thick steel plates having good combination of strength, toughness and weldability have been required for building large container ships. EH36 steel plates with heavy gauge were developed using newly installed accelerated cooling equipment. In order to develop EH40 grade steel, the hardenability of boron were carefully utilized, along with optimizing TMCP processing variables to obtain good mechanical properties and to lessen inhomogeneity in the thickness direction. These thick steel plates showed high strength and good toughness, even at the mid-thickness region, and excellent properties of welded joints at high heat input.