High tensile strength steel plates with excellent HAZ toughness for shipbuilding: JFE EWEL technology for excellent quality in HAZ of high heat inputwelded joints

Abstract

In order to meet the increased heat input in welding for improved productivity of shipbuilding, Steel developed JFE EWEL, a new technology for improving HAZ toughness in high heat input welding. Technical factors of EWEL include the control of grain size in HAZ through optimization of TiN, control of micro structure in HAZ grain through advanced microalloying technology, and optimized alloy design through application of Super-OLAC. By applying EWEL to the steel used in shipbuilding, such as YS390 N/mm 2 class heavy section plate for container ships, low-temperature service steel plate for LPG carriers, and YS355 N/mm 2 class F-grade plate for hull structures, excellent properties in both base plates and welded joints for high heat input welding were achieved.