电气设备GIS和GIL用不同材质波纹管性能研究

Research on Performance of Different Bellows Materials for GIS/GIL

波纹管是电力设备GIS、GIL的重要结构,服役环境复杂,要求材料组织性能稳定,易加工成型,服役过程中温升小,满足不同地区的腐蚀要求。文中选取了304、304L、321、316L、Incoloy 825五种材料为研究对象,测试它们作为波纹管候选材料的性能。利用X射线衍射(XRD)观察了不同变形程度后的组织,发现在304、304L和321不锈钢中发生了塑性诱导相变相变诱导塑性(transformation induced plasticity,TRIP)效应,这3种材料中均出现了α′马氏体,316L不锈钢和825合金中没有发生相变。因此在硬度测试中304、304L、321合金的硬度增幅大于316L和825。采用静态磁性测量等方法研究了材料的磁性变化,发现经形变后Br和Hc均出现不同程度增强,说明不锈钢材料均产生不同程度的磁性。利用电化学测试方法研究了不同材料抗腐蚀性,试验表明5种试验材料在C4以上重污染大气环境均有较好的抗腐蚀性。其中,316L不锈钢表现出最好的耐蚀性能。因此,在变形量较大,腐蚀环境恶劣的情况下推荐使用316L不锈钢。变形量小,腐蚀轻微的时候推荐使用304不锈钢。

Bellows is an important structure of GIS and GIL and,due to complicated service environment,requires stable microstructure performance,good formability,small temperature rise in service and meets excellent corrosion resistance of different regions.In this paper,304 stainless steel,304L stainless steel,321 stainless steel,316L stainless steel and Incoloy 825 are selected as the research objects to test their performance as candidate materials for bellows.The microstructure at specific strain levels is observed by optical microscope(OM)and X-ray diffraction(XRD).It is found that the transformation induced plasticity(TRIP)effect occurs andα′martensite is observed in 304,304L and 321stainless steel.No phase transformation in 316L stainless steel and 825 alloy are found.The hardness increase magnitude in 304,304L and 321 stainless steel are bigger than that in 316L and 825 alloy during the hardness test.The magnetic variation of the material is studied by static magnetic measurement.It is found that both Br and Hc increase in varying degrees after deformation,showing that all candidate materials produce different degrees of magnetism.The corrosion resistance of different materials is studied by electrochemical test,which shows that the five test materials have good corrosion resistance in heavy polluted atmospheric environment above C4,with 316L stainless steel in particular.Therefore,316L stainless steel is recommended in the case of large deformation and harsh corrosive environment and 304 stainless steel is recommended in the case of small deformation and slight corrosion.