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通过拉伸、弯曲、冲击、硬度、金相分析等试验对BS600MCJ4低合金高强钢焊接接头的力学性能和组织形态进行了研究。结果表明,采用ER70-G焊丝焊接时,BS600MCJ4焊接接头具有良好的拉伸、弯曲和冲击性能;其焊缝组织为有少量先共析铁素体、少量无碳贝氏体从晶界伸向晶内,晶内为针状铁素体,个别部位有粒状贝氏体。熔合区及粗晶区组织为粒状贝氏体和少量针状铁素体。正火区组织为索氏体和粒状贝氏体。BS600MCJ4焊接接头的硬度值在243~330 HV之间,焊缝处硬度最高,但与热影响区和母材相差不大,热影响区软化不明显。
The mechanical properties and microstructure of BS600MCJ4 low-alloy high-strength steel welded joints were studied by tensile, bending, impact, hardness and metallographic analysis. The results show that BS600MCJ4 welded joints have good tensile, bending and impact properties when welded with ER70-G wire. The weld microstructure has a small amount of pro-eutectoid ferrite and a small amount of carbon-free bainite extends from the grain boundaries Crystal, intracrystalline acicular ferrite, individual parts of granular bainite. The fusion zone and the coarse grain zone are granular bainite and a few acicular ferrite. Normalizing zone organized sorbite and granular bainite. BS600MCJ4 weld joint hardness value between 243 ~ 330 HV, the highest hardness at the weld, but with heat affected zone and the parent material is not big difference, heat-affected zone softening is not obvious.