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采用高Ni和低Ni含量两种药芯焊丝对30 mm厚海工钢板EQ47进行了热输入量为17 kJ/cm的多层多道气保焊接试验,通过测试焊接接头微观组织、硬度和冲击性能,分析了Ni含量对焊缝和热影响区组织和性能的影响。结果表明,焊接接头焊缝区主要由针状铁素体(AF)和晶界铁素体构成,高Ni含量焊缝中的针状铁素体体积含量高于低Ni含量焊缝,导致高Ni含量焊缝相对于低Ni焊缝具有较高的硬度和低温韧性。冲击试验表明:高Ni含量接头热影响区的冲击性能低于低Ni含量接头,这是由于使用高Ni焊材熔入粗晶区的Ni含量更高,导致粗晶区和临界粗晶区硬度升高,韧性降低。
The high-Ni and low-Ni flux cored wire were used to test the welding quality of 30mm thick sealed steel plate EQ47 with 17 kJ / cm heat input. The effect of Ni content on microstructure and properties of weld and heat affected zone was analyzed. The results show that the weld zone is mainly composed of acicular ferrite (AF) and grain boundary ferrite. The volume fraction of acicular ferrite in the high Ni content weld is higher than that of the low Ni content weld, resulting in high Ni content weld relative to low Ni weld with high hardness and low temperature toughness. The impact tests show that the impact performance of high Ni content heat affected zone is lower than that of low Ni content, which is due to the higher content of Ni which melts into the coarse grain zone with high Ni welding consumables, resulting in the hardness of the coarse grain zone and the critical coarse grain zone Increase, reduce toughness.