Development of YP460 Class Steel Plate with Excellent Brittle Crack Arrestability for Large Container Ships

摘要

This paper presents the development of heavy thickness steel plate with both high arrestability and high tensile properties by means of the texture-controlled Thermo-Mechanical Control Process (TMCP) with optimization of the chemical composition. The developed YP460 (EH47 grade) heavy thickness steel plate has an excellent arrestability of over 15,000 N/mm~(3/2), which is more than double the guidelines on the brittle crack arrest design issued by some classification societies. A characteristic of the plate is a highly oriented transformation texture for the prevention of brittle crack propagation in addition to excellent Charpy impact toughness. The alloy design of the developed steel is relatively high carbon equivalent but low carbon content in order to satisfy the required tensile properties for every thickness portion. The developed steel also exhibits low cold cracking susceptibility equal to that of conventional YP390 steel plates due to its alloy design and consequently good weldability.