It has been reported that low transformation temperature (LTT) weld metals are beneficial to generation of compressive residual stress around weld zone. In this study, the relationship among residual stress, size effect of LTT welded joints with different plate width and thickness as well as martensite start (Ms) temperatures was investigated by experimental and finite-element analysis. It was found that heat dissipation and thermal expansion coefficient of LTT weld metal had a significant impact on residual stress. Welded joint with a small plate width led to greater compressive residual stresses in the LTT weld, which was due to the lower heat dissipation and smaller thermal expansion coefficient of the LTT weld metal in due course of cooling process. Additionally, the finite-element analysis revealed that increasing plate width mainly affected the longitudinal residual stress, while increasing the plate thickness influenced all the residual stress components in the LTT weld. Furthermore, the LTT weld with a lower Ms temperature of 191 °C resulted in greater compressive residual stresses, and was less sensitive to the LTT joint size, as against the Ms temperature of 398 °C.

据报道，低转变温度（LTT）焊接金属有利于在焊接区周围产生压缩残余应力。在这项研究中，通过实验和有限元分析研究了残余应力，不同板宽和厚度的LTT焊接接头的尺寸效应以及马氏体起始温度之间的关系。结果发现，LTT焊接金属的散热和热膨胀系数对残余应力有显着影响。薄板宽度的焊接接头在LTT焊缝中产生更大的压缩残余应力，这是由于在适当的冷却过程中LTT焊缝金属的散热量较小且热膨胀系数较小。此外，有限元分析表明，增加钢板宽度主要影响纵向残余应力，而增加钢板厚度会影响LTT焊缝中的所有残余应力分量。此外，较低的Ms温度为191°C的LTT焊缝会产生更大的压缩残余应力，并且与398°C的Ms温度相比，对LTT接头尺寸的敏感性较低。