This study showed that high-density nano-precipitates, which have not been observed before, formed in the carbon-enriched zone located 20 µm away from the fusion boundary of the dissimilar metal welds of Alloy 52M and A508 steel. The nano-precipitate, which was named as CrC_x in this study, was in a rodlike shape and shorter than 30 nm. The atoms of CrC_x were arranged as a face-centered cubic (FCC) crystal. The CrC_x precipitates have a lattice parameter of 4.08 Å and a cube-on-cube orientation relationship with the austenitic matrix of Alloy 52M. The results will be of great benefit to the development of advanced dissimilar metal welds and new Ni-based alloys serviceable in a harsh environment.

这项研究表明，在距52M和A508合金异种金属焊缝的熔合边界相距20 µm的富碳区中，形成了以前从未观察到的高密度纳米沉淀。纳米沉淀在本研究中被称为CrC _x，呈棒状且短于30 nm。CrC _x的原子排列为面心立方（FCC）晶体。CrC _x析出物的晶格参数为4.08，并且与52M合金的奥氏体基体具有立方对立方取向关系。该结果将对开发先进的异种金属焊缝和可在恶劣环境下使用的新型镍基合金大有裨益。