Effects of rare earth metal addition on the cavitation erosion-corrosion resistance of super duplex stainless steels
Effects of rare earth metal addition on the cavitation erosion-corrosion resistance of super duplex stainless steels
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DOI：
10.1007/bf03186100
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发表时间：
2002-06-01
影响因子：
3.5
通讯作者：
Song, CB
中科院分区：
文献类型：
--
作者：
Shim, SI;Park, YS;Song, CB
诸如AISI 316L的奥氏体不锈钢已经用于其中流体以高速流动的设备中，所述高速流动的流体由于腔的塌陷而能够在金属表面上引起空蚀，其中塌陷是由液体内的局部压力的突然变化引起的。通常AISI 316L易受空蚀影响。本研究的重点是开发一种更好的材料，以取代AISI 316L用于高速流体流动的设备，如叶轮。采用金相、动电位极化、拉伸、X射线衍射和超声空蚀试验等方法研究了稀土对双相不锈钢抗空蚀性能的影响。实验合金被发现具有上级机械性能，由于间隙固溶体强化，通过添加高氮（0.4%），以及通过细化的相和晶粒引起的细REM氧化物和氧硫化物。随着REM含量的增加，耐腐蚀性以平缓的梯度降低。然而，含REM的合金与其它商业合金（SAF 2507、AISI 316 L）相比显示出上级耐腐蚀性。含稀土元素的合金具有优异的力学性能和耐腐蚀性能，因此具有较高的抗空蚀性能。
Austenitic stainless steels such as AISI 316L have been used in equipment in which fluid flows at high speeds which can induce cavitation erosion on metallic surfaces due to the collapse of cavities, where the collapse is caused by the sudden change of local pressure within the liquid. Usually AISI 316L is susceptible to cavitation erosion. This research focuses on developing a better material to replace the AISI 316L used in equipment with high speed fluid flow, such as impellers. The effects of Rare Earth Metal (REM) additions on the cavitation erosion-corrosion resistance of duplex stainless steels were studied using metallographic examination, the potentiodynamic anodic polarization test, the tensile test, the X-ray diffraction test and the ultrasonic cavitation erosion test. The experimental alloys were found to have superior mechanical properties due to interstitial solid solution strengthening, by adding high nitrogen (0.4%), as well as by the refinement of phases and grains induced by fine REM oxides and oxy-sulfides. Corrosion resistance decreases in a gentle gradient as the REM content increases. However, REM containing alloys show superior corrosion resistance compared with that of other commercial alloys (SAF 2507, AISI 316L). Owing to their excellent mechanical properties and corrosion resistance, the alloys containing REM have high cavitation erosion-corrosion resistance.