针对时速250 km/h客运专线铁路道岔台板组焊后焊缝发生的开裂,对焊缝外观质量及显微组织、裂纹形貌和相关焊接件的理化性能进行了分析。结果表明: 台板焊缝开裂位置厚度较小,当焊缝过大和焊接温度过高时极易形成结晶裂纹。在满足技术设计要求的前提下,减小台板焊缝尺寸,可避免焊接时台板焊缝发生开裂。

In view of the weld cracking after assembly welding of the bedplates on the turnouts of 250 km/h passenger dedicated railway line, the appearance quality and microstructure of weld, crack morphology, physical and chemical properties of each related assembly welded parts were analyzed. The results showed that because of the thickness of bedplate weld cracking position was small, when the weld was too large and the temperature of welding was too high, the weld of bedplate was vulnerable to form the crystal crack. With the premise of satisfy the technical design requirements, the weld crack can be avoided by reducing the weld seam size when bedplate welding.