In this study, in-situ heat treatment and high-temperature tensile tests were performed to investigate the effect of an Ni-interlayer on the zinc-assisted liquid-metal-induced-embrittlement (LMIE) susceptibility of 22MnB5 galvanized steel. The heat treatment results indicated that the Ni-interlayer delays the diffusion between liquid Zn and steel substrate, and it can modify the phase composition of the coating. The high-temperature tensile test results showed that the strength and ductility of the 22MnB5 galvanized steel increased as the Ni-electroplating time increased, indicating that the Ni-interlayer could improve the strength and ductility of the 22MnB5 galvanized steel. The fracture type of the galvanized steel was brittle, while that of the Ni-interlayer galvanized steel was ductile, additionally, a U-shaped crack extending to the steel substrate was observed near the fracture of the galvanized steel, whereas no cracks extending to the steel substrate were observed near the fracture of the Ni-interlayer galvanized steel. In general, the Ni-interlayer can reduce the susceptibility of zinc-assisted LMIE; moreover, when the Ni layer was electrodeposited for 8 min, the property of the Ni-interlayer galvanized steel was found to be comparable to those of bare steel.

在本研究中，进行了原位热处理和高温拉伸试验，以研究 Ni 夹层对 22MnB5 镀锌钢的锌辅助液态金属诱导脆化 (LMIE) 敏感性的影响。热处理结果表明，Ni夹层延迟了液态锌与钢基体之间的扩散，并且可以改变涂层的相组成。高温拉伸试验结果表明，22MnB5镀锌钢的强度和延展性随着电镀Ni时间的增加而增加，表明Ni夹层可以提高22MnB5镀锌钢的强度和延展性。镀锌钢的断裂类型是脆性的，而镍夹层镀锌钢的断裂类型是韧性的，此外，在镀锌钢断裂附近观察到延伸至钢基体的U形裂纹，而在Ni夹层镀锌钢断裂附近未观察到延伸至钢基体的裂纹。一般来说，Ni-夹层可以降低锌辅助LMIE的敏感性；此外，当镍层电沉积 8 分钟时，发现镍夹层镀锌钢的性能与裸钢相当。