采用埋弧焊工艺对EH36船板钢进行多道次、大热输入条件下的焊接试验, 研究了焊接接头的显微组织和力学性能。结果表明: 在大热输入条件下, 焊缝组织由晶界铁素体、块状铁素体和少量针状铁素体组成, 不存在侧板条铁素体, 这对焊缝的力学性能有利; 粗晶热影响区是受焊接热输入影响最严重的区域, 冲击韧性最差的区域为焊缝; 焊接接头的最高硬度出现在粗晶区靠近熔合线处, 为222 HV, 最低硬度出现在细晶区, 为181 HV, 未出现焊接软化区。

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 hardness of welded joint appeared in coarse grains zone near fusion line, the value was 222 HV, the lowest hardness appeared in fine grain zone, the value was 181 HV, and the welding softening zone didn′t appear.