(南京理工大學(xué) 機(jī)械工程學(xué)院，南京 210094)
摘 要: 采用浸泡腐蝕、失重腐蝕以及電化學(xué)腐蝕中的動(dòng)電位極化曲線、電化學(xué)阻抗譜等方法研究靜液擠壓AZ80鎂合金經(jīng)350 ℃退火熱處理1、2和4 h后，在pH 6.1的0.1 mol/L Na2SO4溶液中的腐蝕行為。結(jié)果表明：退火熱處理使得擠壓后的AZ80鎂合金晶粒發(fā)生再結(jié)晶，改變AZ80鎂合金的組織和成分分布，可有效提高鎂合金的腐蝕性能；但是熱處理時(shí)間也會(huì)對合金的耐蝕性產(chǎn)生影響，其中經(jīng)(350 ℃,1 h)退火熱處理后，合金自腐蝕電位為-1.4501 V，腐蝕電流密度為0.02323 mA/cm2，耐腐蝕能力顯著提高，表現(xiàn)出較好的綜合性能。
關(guān)鍵字: AZ80鎂合金；靜液擠壓；熱處理；耐腐蝕性能
（College of Mechanical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China）
Abstract:The effect of heat treatment (annealing at 350 ℃ for 1, 2 and 4 h, respectively) on the corrosion behavior of hydrostatic extruded AZ80 magnesium alloy tube was investigated by immersion tests, weightlessness corrosion, potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS) in the 0.1 mol/L Na2SO4 solution at pH of 6.1. The results indicate that the re-crystallization occurs in the hydrostatic extruded AZ80 magnesium alloy during annealing, which can effectively improve the corrosion performance of magnesium alloy for changing microstructure and composition distribution. However, the duration of heat treatment would affect the corrosion resistance of alloy, comparing to other samples heat treated for different times, the annealing one after 1h heat treatment time at 350 ℃ shows good comprehensive performance at the corrosion potential of -1.4501 V, corrosion current density of 0.02323 mA/cm2.
Key words: AZ80 magnesium alloy; hydrostatic extrusion; heat treatment; corrosion resistance
