17-4PH stainless steel coatings is widely used in the field of laser repair due to its excellent performance. In the service process, the coatings not only have excellent mechanical properties but also ensure the formation of an excellent metallurgical bond between the coatings and the substrate. In this paper, the formability, microstructure evolution, texture characterization, microhardness and interface bonding strength of laser cladding 17-4PH stainless steel coatings under different laser powers are studied. A novel test method and related fixture are designed to analyze the interface fracture behavior of T-shaped specimens and evaluate the bonding strength. The relationship between microstructure and interfacial bonding strength of T-shaped specimens is investigated by electron backscattering diffraction (EBSD) and a universal testing machine. The higher stress concentration at the interface and heat-affected zone has been found by comparing the coatings. When the laser power is 2200 W, the microhardness and interfacial bonding strength are higher than other specimens, which are 450 HV and 908 MPa, respectively. This phenomenon is due to the appropriate laser power refines grains and reduces micro defects at the interface, which all contribute to improving the interfacial bonding strength. Fracture analysis shows that the combination of microvoids and unmelted powder contributed to accelerating the propagation of cracks.

17-4PH不锈钢涂层以其优异的性能被广泛应用于激光修复领域。在服役过程中，涂层不仅具有优良的力学性能，而且保证涂层与基体之间形成优良的冶金结合。本文研究了激光熔覆17-4PH不锈钢涂层在不同激光功率下的成形性、组织演变、织构表征、显微硬度和界面结合强度。设计了一种新的测试方法和相关夹具来分析 T 形试样的界面断裂行为并评估结合强度。通过电子背散射衍射(EBSD)和万能试验机研究了T形试样的微观结构与界面结合强度之间的关系。通过比较涂层，发现界面和热影响区的应力集中较高。当激光功率为2200 W时，显微硬度和界面结合强度高于其他试样，分别为450 HV和908 MPa。这种现象是由于适当的激光功率细化了晶粒并减少了界面处的微缺陷，这些都有助于提高界面结合强度。断裂分析表明，微孔和未熔化粉末的结合有助于加速裂纹的扩展。通过比较涂层，发现界面和热影响区的应力集中较高。当激光功率为2200 W时，显微硬度和界面结合强度高于其他试样，分别为450 HV和908 MPa。这种现象是由于适当的激光功率细化了晶粒并减少了界面处的微缺陷，这些都有助于提高界面结合强度。断裂分析表明，微孔和未熔化粉末的结合有助于加速裂纹的扩展。通过比较涂层，发现界面和热影响区的应力集中较高。当激光功率为2200 W时，显微硬度和界面结合强度高于其他试样，分别为450 HV和908 MPa。这种现象是由于适当的激光功率细化了晶粒并减少了界面处的微缺陷，这些都有助于提高界面结合强度。断裂分析表明，微孔和未熔化粉末的结合有助于加速裂纹的扩展。这种现象是由于适当的激光功率细化了晶粒并减少了界面处的微缺陷，这些都有助于提高界面结合强度。断裂分析表明，微孔和未熔化粉末的结合有助于加速裂纹的扩展。这种现象是由于适当的激光功率细化了晶粒并减少了界面处的微缺陷，这些都有助于提高界面结合强度。断裂分析表明，微孔和未熔化粉末的结合有助于加速裂纹的扩展。