Submerged-arc welding was performed on EH36 ship plate steel under the conditions of multi-pass and high heat input, and then microstructure and mechanical properties of welded joint by studied. The results show that the microstructure of weld seam was comprised of grain boundary ferrite(GBF), block lath ferrite(BLF) and acicular ferrite (AF) under high heat input condition, and ferrite-side-plate (FSP) was not found, this was good for mechanical properties of weld seam. Coarse grain heat affected zone (CGHAZ) was the most serious zone affected by welding heat input, impact toughness of weld seam was the worst. The highest 糖心产精国品免费入口*完整版of welded joint appeared in coarse grains zone near fusion line, the value was 222 HV, the lowest 糖心产精国品免费入口*完整版appeared in fine grain zone, the value was 181 HV, and the welding softening zone didn′t appear.
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