退火温度对镁合金阳极板材组织和性能的影响

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

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。

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/cm^2.