退火温度对镁合金阳极板材组织和性能的影响

对镁合金热轧板材在不同温度进行退火处理,采用恒电流扫描法、动电位极化扫描法和浸泡法研究不同退火温度对其在3.5%(质量分数)NaCl中的电化学性能和自腐蚀性能的影响;采用光学显微镜、扫描电镜和X射线衍射仪对其显微组织和腐蚀形貌进行观察。结果表明:镁合金阳极板材在退火过程中发生静态再结晶,经250℃、300℃退火1 h,合金板材发生完全再结晶;经300℃退火1 h后,镁合金阳极板材的电化学活性最好,放电稳定电位达1.654 V(vs SCE),但其耐蚀性能最差,腐蚀电流密度为180.38μA/cm2。

Effect of annealing temperatures on microstructure and properties of magnesium alloy anode sheet

Annealing treatment was carried out on the hot-rolled magnesium alloy anode sheet at different temperatures.The effects of different annealing temperatures on the electrochemical and self-corrosion behavior of magnesium alloy anode were investigated by galvanostatic tests,potentiodynamic plorization and immersion tests in 3.5%(mass fraction) NaCl.The microstructure and the corroded surface of the experimental specimens were observed by optical microscopy,scanning electron microscopy and X-ray diffractometry.The results show that static recrystallization occurs during the annealing treatment,the magnesium alloy sheet shows completely recrystallized microstructure after being annealed at 250 and 300 ℃ for 1 h.After being annealed 300 ℃ for 1 h,the magnesium alloy sheet has the best electrochemical activity,whose discharge electrode potential can be up to ?1.654 V(vs SCE),but its corrosion resistance is the worst and the corrosion current density is 180.38 μA/cm2.