Abstract A thermal-metallurgical-mechanical model was developed to study the effects of dilution in each weld pass for multipass gas tungsten arc and submerged arc welding in low alloy steel (i.e. SA508) plates. Hardness distributions and residual stresses were measured on the transverse sections perpendicular to the welding direction of the manufactured weldments. The predicted hardness and residual stresses were compared with the measurement data and shown to be reasonably accurate. The results showed that dilution can significantly affect both the hardness and the residual stress field in the weld metal. It was found that, for the base and filler materials used, increased dilution led to greater weld-metal hardness and reduced the magnitude of tensile stress or promoted compressive stress in the as-deposited and reheated weld metals. This mechanical behaviour is associated with the tendency for diluted weld metal to experience delayed austenite decomposition, owing to the high hardenability of SA508 steel relative to the filler materials used. Although dilution is irrelevant for the hardness of the base material and its transformation products adjacent to the weld metal, it affected the full-field residual stresses via the equilibrium interaction between the stresses in the base and weld metals.

中文翻译：

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稀释对多道钢焊件硬度和残余应力的影响

摘要 为了研究低合金钢（即SA508）板多道钨极气体保护焊和埋弧焊各焊道中稀释的影响，建立了热-冶金-机械模型。在垂直于制造焊件焊接方向的横截面上测量硬度分布和残余应力。预测的硬度和残余应力与测量数据进行了比较，结果显示相当准确。结果表明，稀释可以显着影响焊缝金属的硬度和残余应力场。研究发现，对于所使用的母材和填充材料，稀释度的增加会导致焊缝金属硬度增加，并降低拉伸应力的大小或促进沉积态和再加热焊缝金属中的压应力。由于 SA508 钢相对于所用填充材料的高淬透性，这种机械行为与稀释焊缝金属经历延迟奥氏体分解的趋势有关。尽管稀释与母材的硬度及其邻近焊缝金属的转变产物无关，但它通过母材和焊缝金属应力之间的平衡相互作用影响了全场残余应力。