目的 提高 0Cr18Ni9Ti 奥氏体不锈钢的抗高温摩擦性能。 方法 利用等离子渗金属技术在不锈钢表面等离子渗铪,之后进行固体渗碳,在 HT-500 型球-盘磨损试验机上进行高温摩擦磨损实验,分析其高温摩擦性能及摩擦机制,并与不锈钢基体试样及不锈钢渗铪试样进行对比。 结果 渗铪试样的渗层厚度约为 45 μm,渗铪+渗碳试样的渗层厚度达 100 μm。 渗铪+渗碳层弥散分布着许多粒状和短棒状碳化物颗粒,碳化物类型主要为 MC 型、M7C3 型和 M23C6 型。 基材的摩擦曲线波动起伏大;渗铪试样的摩擦系数较大,但磨损微观表现平稳;渗铪+渗碳试样的摩擦系数最小。 磨损失重由大到小依次为:基材>渗铪试样>渗铪+渗碳试样。 在 300,500 ℃ 下,渗铪试样的耐磨性相对基材分别提高至 1. 47 倍和 1. 94倍,渗铪+渗碳试样分别提高至 2. 13 和 2. 28 倍。 基材划痕尺寸宽且较深;渗铪试样的表面硬度提高,且摩擦磨损过程中出现了合金氧化物;渗铪+渗碳试样的表面硬度高,基体韧性好,仅出现了很浅且窄的磨痕。 结论 通过等离子渗铪及离子渗铪+固体渗碳,均能提高不锈钢表面的抗高温摩擦性能,相比之下,离子渗铪+固体渗碳的效果更好。

Objective To improve high-temperature wear properties of 0Cr18Ni9Ti austenite stainless steel. Methods Wear properties of stainless steel (substrate for short), and the substrates after treatment with plasma surface hafniuming and carburization were investigated on HT-500 ball-disc wear tester. The high-temperature friction properties and friction mechanism were analyzed and compared with those of the stainless steel substrate and stainless steel with surface hafniuming. Results The thickness of Hf-alloyed layer was 45 μm, and that of Hf+C layer was 100 μm. The Hf+C layer dispersed a large amount of granular particles and short sticks of carbide, and the main types of carbide were MC, M7 C3 and M23 C6 . The wear curve of the substrate showed large fluctuation, the Hf-alloyed sample had greater friction coefficient but the wear microstructure was stable; the Hf+C-treated sample had the minimum friction coefficient. The wear loss was in the order of substrate> Hf-alloyed sample> Hf+C-treated sample. The relative wear resistance of Hf-alloyed sample at 300 ℃ and 500 ℃ were 1. 47 and 1. 94 times of the substrate, while that of Hf+C-treated sample was about 2. 13 and 2. 28 times of the substrate. The scratches of the substrate were wide and deep. The surface hardness of Hf-alloyed sample was improved, and alloy oxide was generated during the friction wear process. The Hf+C-treated sample had high surface hardness and the matrix had good toughness, the scratches were shallow and narrow. Conclusion Hafniuming and carburization could improve the high-temperature wear properties of the surface of 0Cr18Ni9Ti austenite stainless steel, and Hf+C-treated sample showed better wear performance.