层流冷却辊的表面质量直接影响连铸和热轧生产线中钢带的最终质量。本研究采用药芯焊丝电弧堆焊（FCAW）制备了不同 Cr 和 B 含量的 Fe-Cr-Ni-Mo-B 耐磨堆焊层。系统研究了合金成分对堆焊层微观组织演变、碳化物和硼化物形貌以及磨损行为的影响，特别强调了微观组织特征与耐磨性之间的关系。将 B 含量从 0.3 wt% 提高到 0.6 wt% 促进了硼化物的形成，并将共晶 M₂B 从粗大的离散颗粒转变为细小且相对连续的网络结构。同时观察到微观组织细化，显微硬度从 747.7 HV0.3 提高到 810.7 HV0.3。在约 0.6 wt% B 条件下，将标称 Cr 含量从 15 wt% 提高到 19 wt%，共晶硬质相逐渐粗化，并伴随由细互联网络向粗骨架状和板条状结构的形貌转变。
The surface quality of laminar cooling rolls directly affects the final quality of steel strips produced in continuous casting and hot rolling lines. In this study, Fe-Cr-Ni-Mo-B wear-resistant cladding layers with different Cr and B contents were fabricated by flux-cored arc welding (FCAW). The effects of alloy composition on microstructural evolution, carbide and boride morphology, and wear behavior of the cladding layers were systematically investigated, with particular emphasis on the relationship between microstructural characteristics and wear resistance. Increasing the B content from 0.3 wt% to 0.6 wt% promoted the formation of borides and transformed eutectic M₂B from coarse discrete particles into a fine and relatively continuous network structure. Meanwhile, microstructural refinement was observed, and the microhardness increased from 747.7 HV 0.3 to 810.7 HV 0.3 . With increasing nominal Cr content from 15 wt% to 19 wt% at approximately 0.6 wt% B, the eutectic hard phases progressively coarsened, accompanied by a morphological transition from a fine interconnected network to coarse skeletal and plate-like structures. The retained austenite fraction also increased, while the microhardness decreased to 697.1 HV 0.3 . Among the investigated cladding layers, Fe-15Cr-0.6B-2Ni-2Mo exhibited the best wear resistance, which was associated with its fine and relatively continuous eutectic borides and martensitic matrix. The results indicate that wear resistance is governed not only by the fraction of hard phases but also by their morphology, distribution, and interaction with the supporting matrix. After undergoing high-temperature wear at 600 °C, more pronounced subsurface damage and surface oxidation were observed, demonstrating a significant influence of elevated temperature on the wear behavior. These findings provide guidance for the composition and microstructure design of FCAW Fe-based wear-resistant cladding layers for laminar cooling roll applications.