스팀터빈 밸브용 Class II 합금의 Plasma 이온질화 처리에 관한 연구
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We experimented Pre-sputtering condition for a best suited ion nitride justice development of a class alloy. and the justice variable and experimented and an each condition for the ion nitride. The result is as follows. Gas mixing ratio which is most efficient when we do Pre-sputtering was Ar : H₂= 3 : 1. and the temperature was 500℃, the vacuum ratio was 1.5 torr. the time's 60minute was most efficient. Gas mixing ratio which is most efficient when we do ion nitride condition was N₂: H₂= 3 : 1. The vacuum ratio was most the 3torr a superiority low. We expressed most good effectiveness in a temperature was 590℃. EDS analysis result is as follows. Cr was contained in nitride layer. and Cr Deplet Zone was observed in a most outer layer. The existence of my second layer was verified between a matrix and nitride layer. We could confirm the nitride of CrN FeN total in XRD analysis result. An activation energy for a nitride layer formation of ClassII alloy about 65KJ/mol. The high temperature micro hardness test results was 500 to 600 at 538℃. This shows extremely in the high temperature the degrade of the skewness extreme. Gas nitride sample was increased at the high temperature, high pressure oxidation test result. Strong Fe₂O₃ peak was observed and in all samples. This is seemed to be processed together with the oxidation and corrosion. A polarization measurement result's corrosion speed of a nothing processing was most fast and we found that nitride layer was protection layer so the corrosion could know therefore that we are reduced.