Welding of high-strength steels can result in large tensile strains as the base metal and filler material cool from their molten state. To combat these large tensile strains, low-transformation-temperature (LTT) metal fillers have been proposed. These fillers undergo a martensitic phase transformation at a lower temperature which can ultimately reduce the tensile strain or can even introduce compressive strain adjacent to the weld metal. However, the process for optimizing the composition of the LTT material, as well as various weld parameters for each unique weld geometry, can be quite expensive, especially if the acceptance criterion requires using neutrons, x-ray beams, or destructive techniques to characterize residual stresses. This work describes a simple, low-cost method for quantifying residual stresses and phase transformations in situ during welding. Spatially distributed fiber-optic sensors were bonded to a cast iron plate, along with tack-welded thermocouples,...

中文翻译：

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使用空间分布的光纤应变传感器原位测量焊接过程中的相变和残余应力演变

高强度钢的焊接会导致较大的拉伸应变，因为贱金属和填充材料会从熔融状态冷却下来。为了抵抗这些大的拉伸应变，已经提出了低转变温度（LTT）金属填料。这些填料在较低的温度下发生马氏体相变，最终可以降低拉伸应变，甚至可以在焊接金属附近引入压缩应变。但是，优化LTT材料成分以及每种独特焊缝几何形状的各种焊接参数的过程可能会非常昂贵，尤其是在接受标准要求使用中子，X射线束或破坏性技术来表征残留物的情况下。压力。这项工作描述了一个简单的，一种用于量化焊接过程中残余应力和相变的低成本方法。空间分布的光纤传感器与点焊热电偶，铸铁板结合在一起。