Abstract: In order to study the effect of B element on the structure and performance of stainless steel flux-cored wire surfacing alloy, stainless steel alloy layers with different B contents were prepared on the surface of carbon steel plate by MIG welding, and the microstructure, phase composition, hardness and wear resistance of the surfacing layer were analyzed.The results show that the matrix of the surfacing layer is austenite, and the hard phase is M₂B phase and a small amount of Fe₃(C, B) phase.Adding a proper amount of B can significantly improve the hardness and wear resistance of the surfacing layer.When the B content is 2%, the performance of the surfacing layer is best, the maximum hardness value reaches 43.5 HRC, and the wear amount is minimum.With the increase of temperature, the abrasive wear of the surfacing layer alloy is gradually transformed from abrasive wear to adhering wear, and the wear amount gradually increases.