Research and Development > JFE TECHNICAL REPORT >JFE TECHNICAL REPORT No.20 March 2015 - Special Issue on “Steel Plates” and “Welding and Joining” > Development of YP460 N/mm² Class Heavy Thick Plate with Excellent Brittle Crack Arrestability for Mega Container Carriers

No.20 March 2015 - Special Issue on “Steel Plates” and “Welding and Joining”

Development of YP460 N/mm² Class Heavy Thick Plate with Excellent Brittle Crack Arrestability for Mega Container Carriers

HASE Kazukuni       HANDA Tsunehisa       ETO Taiki

Abstract

YP460 N/mm² class heavy thick plate with excellent crack arrestability for mega container carriers has been developed. Advanced alloy design and an optimized controlled rolling and cooling process using Super-OLAC^TM (On-Line Accelerated Cooling) are applied to obtain highly oriented textures parallel to the surface of the plate, which are effective to prevent brittle crack propagation. The crack arrest toughness (Kca at −10°C) of the developed steel is 16 800 N/mm^3/2, which is more than double that of the guidelines on brittle crack arrest design issued by Class NK. The large scale duplex ESSO test, assuming the structure of the hatch side coaming of container carriers, was also carried out, and the result revealed that the developed steel plate has very good performance to stop brittle crack propagation. The developed steel plate is supposed to be utilized to ensure the safety of mega container carriers against brittle fracture.

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