중탄소강 SAW 용접금속의 응고 균열 발생에 미치는 용접재료의 영향 |
방국수1, 송우현2, 정홍철2 |
1부경대학교 신소재시스템공학과 2포스코 기술연구원 |
Effects of Welding Consumables on the Solidification Cracking in SAW Weld Metal of Medium Carbon Steel |
Kook-soo Bang1, Woo-hyun Song2, Hong-chul Jung2 |
1Department of Materials System Engineering, Pukyong National University, Busan 48547, Republic of Korea 2Technical Research Laboratories, POSCO, Pohang 37859, Republic of Korea |
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Received: 7 September 2017; Accepted: 6 November 2017. Published online: 5 February 2018. |
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ABSTRACT |
The effects of submerged-arc welding consumables, wire and flux, on solidification cracking in the weld metal of medium-carbon steel were investigated. It showed that weld metal with a greater amount of C, S, and P had a wider brittleness temperature range, BTR, which resulted in longer total and maximum crack lengths in Varestraint tests. To determine the effect of flux on the amount of C, S, and P in the weld metal, transfers of the elements between the slag and the weld metal were evaluated. While C and S were removed from the weld metal to the slag, P was added from the slag to the weld metal. The amount of each element removed or added, however, was dependent on the basicity of the flux used. As the flux became more basic, more S was removed and less P was added, resulting in less S and P in the weld metal. In contrast, with increasing flux basicity, less C was removed, leaving a larger amount of C in the weld metal. Therefore, to minimize the amounts of these elements in the weld metal, in addition to the wire used, the flux basicity should also be carefully considered. |
Keywords:
metals, welding, solidification, SIMS, element transfer. |
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