Abstract: High-frequency induction cladding technology is one of the main directions for the development of high-temperature anti-corrosion technology for the four heating surfaces of boilers. However, when the high-frequency induction coil heats the coating on the outer wall of the tube, the inner wall of the tube is also heated, causing oxide scale on the surface of the inner wall of the tube.By testing the surface hardness and the depth of the decarburized layer, the influence of the oxide scale on the performance of the inner wall of the tube was evaluated.The results show that when the temperature of the inner wall of the tube exceeds 580 ℃, three oxide films of FeO, Fe₃O₄ and Fe₂O₃ are sequentially formed from the surface of the inner wall of the tube to the outside, with a thickness ratio of about 1∶10∶100.Although FeO is thin, it has a loose structure, a crystal lattice with many defects, and is unstable and easy to decompose, so it is easy to fall off from the inner wall surface of the tube, which is the main factor causing the tube burst accident. The method of nitrogen protection is used to effectively suppress the generation of oxide scale during the induction cladding process. This method also suppresses the generation of oxide scale on the back of the tube row, and the experiment proves that its effect is significant.