摘要： 采用空气喷涂法在 SPA-H 含镍合金钢表面制备了 Mg-Al-O 高温防护涂层，研究了涂层对 SPA-H 合金钢的高温氧化行为及氧化皮粘附性的影响。 采用金相显微镜对喷涂样和空白样的剖 面和表面形貌进行表征，采用 SEM 和 EDX 分析氧化皮中元素分布，研究 Mg-Al-O 涂层的作用过程和防护机理。 结果表明:涂层可以大幅度提高 SPA-H 合金钢高温耐氧化腐蚀能力，在1 100 °C、 1 200 °C 、1 250 °C 下恒温 2 h，降低氧化烧损分别为 47.2%、41.3%、 41.5%。 涂层在钢坯表面和基体 探 生成的氧化皮发生反应，生成尖晶石结构，抑制阳离子扩散速率。 同时通过减少基体和涂层界面处Ni、Cr 氧化物的生成量，改善热轧前氧化皮的剥落性能，提高后期产品表面质量。

关键词: 含镍合金钢, 高温防护涂层, 粘附性

Abstract: A high temperature protective coating on the surface of SPA-H alloy steel was prepared by air spraying method The coating was mainly consisted of magnesia and alumina.The effect of coatings on the high temperature oxidation behavior of SPA-H and the adherence of scale was investigated. Metallurgical microscopy was used to characterize the cross section and surface of the coated and control samples. SEM and EDX were used to study the element distribution in oxide scale and provided evidence for the reacting process of coatings and the mechanism of oxide resistance. The experimenta result showed the coating could enhance oxidation resistance effectively. The metal loss of coated samples was decreased by 47.2%, 41.3% and 41. 5% as compared with the bare samples when isothermal oxidation in air was at 1 100℃, 1 200℃, 1 250 ℃ for 2 h respectively. The coating could react with the scale formed on the surface of the steel to generate spinel structure compound which could decrease the diffusion velocity of cation during oxidation. Ni and Cr oxide enriched at the surface of scale and substrate were reduced so that the scale could be easily broken before hot rolling and the surface quality of later product was improved.

Key words: Ni-contained steel, high temperature oxidation resistant coating, adhesion