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为探讨铈对铬镍奥氏体耐热钢抗氧化腐蚀性能的影响,研究了添加铈的Sandvik253MA钢在900℃熔融Na_2SO_4中的抗氧化腐蚀性能。试验表明,添加铈后提高了钢的抗氧化腐蚀性能,使其优于铬、镍含量较高的AISI310S钢。铈在钢中的主要作用是加速保护性氧化膜的生成,使氧化物的晶粒细化、致密而又均匀,增强氧化皮的抗剥落性。文中讨论了铈对提高耐热钢抗氧化腐蚀性能的作用机理。 许多研究表明,在奥氏体耐热钢中加入少量的稀土元素,可提高钢在大气中的抗氧化能力。实际上由于燃料中一般都含有硫,所以耐热钢更多地是在含硫的氧化气氛中工作,高温时,与氧化同时存在的硫化将加速钢的腐蚀破坏。本试验目的是探讨在氧化、硫化同时存在的条件下,铈对耐热钢抗氧化腐蚀性能的影响及其作用机理。 一、材料及试验方法 (一)试验研究用材料 采用添加铈的瑞典Sandvik253MA作为试验用钢,为此,瑞典金属研究所提供了三个炉号的工业生产的钢料,为了与高铬镍奥氏体钢(AISI310S)进行对比试验,研究铈含量对钢的性能的影响,用20kg真空感应炉冶炼了三个炉号的钢料,锻成φ20mm的棒材。各炉号的化学成分列于表1。试样在加工前需经1100℃保温20分钟水冷处理,再经金相观察,确认各试料均为全奥氏体组织,其夹杂含量无明显差别,奥氏体晶粒尺寸和
In order to investigate the effect of cerium on the corrosion resistance of austenitic heat-resisting steel, the corrosion resistance of Sandvik253MA steel with cerium to molten Na_2SO_4 at 900 ℃ was studied. Experiments show that the addition of cerium increases the oxidation resistance of steel, making it better than the high content of chromium and nickel AISI310S steel. The main role of cerium in steel is to accelerate the formation of a protective oxide film, to refine the grain of the oxide, to be dense and uniform, and to enhance the spallation resistance of the scale. This paper discusses the mechanism of cerium to improve the oxidation resistance of corrosion-resistant steel. Many studies have shown that the addition of a small amount of rare earth elements in austenitic heat-resistant steels can increase the oxidation resistance of steel in the atmosphere. In fact, the fuel generally contains sulfur, so the heat-resistant steel is more in sulfur-containing oxidizing atmosphere work, at high temperatures, the simultaneous presence of oxidation will accelerate the destruction of steel corrosion. The purpose of this experiment is to investigate the effect of cerium on the oxidation and corrosion resistance of heat-resisting steel and its mechanism under the simultaneous oxidation and sulfidation conditions. I. Materials and Test Methods (I) Materials for Test and Study Using Swedish Sandvik253MA with cerium as the test steel, the Swedish Institute of Metals provided three industrial heat-treated steels for high-chromium nickel austenite Steel (AISI310S) comparative test to study the impact of cerium content on the performance of steel, with a 20kg vacuum induction furnace smelting three heat No. steel, forged into φ20mm bar. The chemical composition of each heat is given in Table 1. Sample before processing to be 1100 ℃ for 20 minutes water cooling treatment, and then metallurgical observation confirmed that all samples are all austenite, the inclusion content was no significant difference in austenite grain size and