[Research Papers] Effects of Heat Input and Interpass Temperature on the Strength and Impact Toughness of Multipass Weld Metal in 570㎫ Grade Steel

Byun, Ji-chul; Bang, Kook-soo; Chang, Woong-sung; Park, Chul-gyu; Chung, Woo-hyun

Journal of KWJS 2006;24(1):64-70.
Published online April 3, 2006.

[연구논문] 570㎫급 용접구조용강 다층 용접금속의 강도 및 충격인성에 미치는 입열 및 패스간 온도의 영향

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[Research Papers] Effects of Heat Input and Interpass Temperature on the Strength and Impact Toughness of Multipass Weld Metal in 570㎫ Grade Steel

Ji-chul Byun, Kook-soo Bang, Woong-sung Chang, Chul-gyu Park, Woo-hyun Chung

Abstract

570㎫ grade weldable steels were gas metal arc welded with various heat inputs and interpass temperatures using flux cored wires. Effects of heat input and interpass temperature on the strength and impact toughness of weld metal were investigated in terms of microstructural change, recovery of alloying elements, and the amount of reheated weld metal. Increase of heat input and interpass temperature resulted in decrease of weld metal strength. This is because of the small amount of acicular ferrite, large columnar size and low recovery of alloying elements such as manganese and silicon. In addition to the microstructural change, weld metal toughness was also influenced by the deposition sequence. It increased with an increase of the amount of reheated weld metal.