喷丸处理对S30432钢650℃蒸汽氧化行为的影响

Effects of Shot Peening on Oxidation Behavior of S30432 Steel in Steam at 650℃

目的提高S30432钢的抗蒸汽氧化性能。方法对S30432钢管进行内表面喷丸处理。在蒸汽氧化实验平台上,对喷丸和未喷丸的S30432钢管进行蒸汽氧化实验,对比研究了其在650℃水蒸汽中的氧化行为。用分析天平测量了试样的增重变化,通过扫描电镜观察了氧化皮表层形貌和氧化层显微结构。结果未喷丸的S30432钢管氧化增重呈抛物线规律,而喷丸后的试样具有完全抗氧化性。未喷丸S30432钢试样表面生成富Fe氧化物,在200 h左右发生失稳氧化,氧化皮快速增厚,500 h时氧化皮厚度达到13μm。喷丸处理后,氧化皮富Cr且很薄,约0.5μm,具有良好的保护性。结论喷丸处理能够显著地提高S30432钢的抗蒸汽氧化性能,通过抑制失稳氧化的发生,使表面快速生成完整的富Cr氧化皮。

The work aims to improve steam oxidation resistance of S30432 steel. Surface shot peening was applied to inside surface of S30432 steel. Steam oxidation experiment was performed to shot-peened and untreated S30432 steel tubes steam oxidation experimental platform, and oxidation behavior of two samples was comparatively studied at 650 ℃ in steam. Weight gain changes of the samples were measured with analytical balance. Surface morphology and microstructure of oxide scale were observed with scanning electron microscope. The untreated S30432 steel exhibited parabolic oxidation kinetics while the treated S30432 steel exhibited complete oxidation resistance. Fe-riched oxide fromed on the surface of the untreated S30432 sample, and the scale thickened quickly due to instability oxidation after nearly 200 h and was 13 μm after 500 h. The treated sample had very thin（about 0.5 μm thick） Cr-enriched scale which exhibited good protective effects. Shot peening treatment can significantly improve steam oxidation resistance of S30432 steel, and generate complete Cr-enriched scale on the surface rapidly by inhibiting instability oxidation.