Compact endless cast and rolling mill (CEM) is an innovative process to manufacture a hot-rolled steel strip by combining casting and hot-rolling processes. However, the yield point phenomenon (YPP) of low carbon steel strip-processed by CEM induces a negative effect in the steel product and an additional post-process is required to remove the YPP. In this study, the influence of the dislocation density and the grain interior solute atoms on the yield point elongation (YPE) of low carbon steels were quantitatively investigated using 3-dimensional atom probe tomography analysis and X-ray convolutional multiple whole profile fitting. The YPE of low carbon steel is suppressed as the dislocation density increases and carbon atom content decreases. Because the dislocation density of low carbon steel by the CEM process is increased by lowering the processing temperature, the yielding behavior of the CEM products can be eliminated without any additional post-processing. The quantitative study on the carbon/dislocation density and YPP of low carbon steel not only represents the theoretical basis of the role of carbon-dislocation interaction on YPP but also provides an effective solution to optimize the CEM process for superior products.

紧凑型无头连铸轧机（CEM）是一种创新工艺，通过结合铸造和热轧工艺来制造热轧钢带。但是，通过CEM处理的低碳钢带材的屈服点现象（YPP）会对钢材产生负面影响，因此需要额外的后处理才能去除YPP。在这项研究中，使用三维原子探针层析成像分析和X射线卷积多重整体轮廓拟合，定量研究了位错密度和晶粒内部溶质原子对低碳钢屈服点伸长率（YPE）的影响。随着位错密度的增加和碳原子含量的减少，低碳钢的YPE受到抑制。由于通过降低加工温度可以提高CEM工艺产生的低碳钢的位错密度，因此无需任何其他后处理即可消除CEM产品的屈服行为。对低碳钢的碳/位错密度和YPP的定量研究不仅代表了碳-位错相互作用对YPP作用的理论基础，而且为优化优质产品的CEM工艺提供了有效的解决方案。