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利用高功率半导体激光器在Q235钢基体上制备哈氏合金C22涂层,研究涂层在静态和空化盐酸、硫酸和硝酸溶液中的腐蚀行为。电化学结果表明:涂层在静态酸溶液中比在空化酸溶液中具有更强的抗腐蚀性能。在以上的每种条件下,涂层抗腐蚀性能由强到弱的顺序均为硝酸、硫酸和盐酸溶液。涂层在空化盐酸溶液中出现冲蚀形貌和严重的晶间腐蚀。这主要与盐酸溶液中存在活性离子以及空化泡崩溃时的力学作用有关。然而,经过空化硝酸溶液腐蚀的涂层表面几乎没有变化。结果表明,空化作用和酸溶液性质的共同作用决定涂层腐蚀的发展。由于在表面形成稳定的致密氧化膜,哈氏合金C22涂层在氧化性酸溶液中表现出更优越的抗腐蚀性能。
The Hastelloy C22 coating was prepared on a Q235 steel substrate by using a high power semiconductor laser to study the corrosion behavior of the coating in static and cavitating hydrochloric, sulfuric and nitric acid solutions. Electrochemical results show that the coating has stronger corrosion resistance in static acid solution than in cavitation acid solution. In each of the above conditions, the corrosion resistance of the coating from strong to weak in the order of nitric acid, sulfuric acid and hydrochloric acid solution. The coating appears cavitation in the hydrochloric acid solution morphology and severe intergranular corrosion. This is mainly related to the presence of active ions in the hydrochloric acid solution and the mechanical action of cavitation bubbles collapsing. However, there was almost no change in the surface of the coating after cavitation nitric acid solution. The results show that the combined effect of cavitation and acid solution determines the development of coating corrosion. The Hastelloy C22 coating exhibits superior corrosion resistance in oxidizing acidic solutions due to the formation of a stable dense oxide film on the surface.