拋光工藝對690合金傳熱管晶間腐蝕指標的影響

Effect by Buffing Treatment on Intergranular Corrosion（IGC） Property of 690 Alloy Tube for Heat-exchanging Service

摘要: 對時效處理后的690合金傳熱管，在拋光處理前后分別按65% HNO₃浸泡法和電化學(xué)再活化法（EPR法）進行晶間腐蝕試驗，分析拋光工藝對690合金傳熱管晶間腐蝕指標的影響。試驗結(jié)果表明：在65% HNO₃浸泡試驗條件下，拋光處理對690合金傳熱管的晶間腐蝕性能無明顯影響；在EPR電化學(xué)法試驗條件下，隨著拋光次數(shù)的增加，活化電流降低并趨于穩(wěn)定，而拋光后管材的表面粗糙程度是影響電化學(xué)腐蝕性能的主要因素。

Abstract: The 690 alloy tube for heat-exchanging service as aging-treated is subjected to the IGC test with the soaking（65%HNO₃）method before buffing，and the electrochemical（EPR）method after buffing in order to investigate how the buffing process affects the IGC property of it. The test result shows that with the soaking （65%HNO₃） method，little effect is found，while with the electrochemical（EPR）method，such a fact is identified that along with increasing of the buffing frequency，the activation current strength is reduced and going to be finally stabilized. Also identified via the test is that the surface roughness level of the buffed material plays a major role which affects the electrochemical corrosion property of the tube.