T6处理对真空压铸AM50镁合金腐蚀行为的影响

为了研究不同时效工艺对真空压铸AM50镁合金耐蚀性的影响,通过静态失重实验和电化学实验研究了T6处理后AM50镁合金在Na Cl溶液中的腐蚀行为.结果表明,合金经过170和230℃时效处理后腐蚀速率的变化情况基本类似,均为先降低后升高,最后达到一个稳定值.但经过230℃时效处理后合金的耐蚀性远差于经过170℃时效处理后的情况,且达到腐蚀速率最低点所需时间更长.不同时效处理后的合金具有相似的电化学腐蚀行为,腐蚀电位无明显变化规律,而腐蚀电流密度与腐蚀速率的变化趋势近乎一致.腐蚀速率随腐蚀时间的延长而下降,并最终保持一个较为稳定的数值.此外,合金腐蚀速率的理论值和实测值相吻合.

Effect of T6 treatment on corrosion behavior of vacuum die casting AM50 magnesium alloy

In order to determine the effect of different aging treatments on the corrosion resistance of vacuum die casting AM50 magnesium alloy, the corrosion behavior of AM50 magnesium alloy subjected to T6 treatment in NaCl solution was studied through static weight loss and electrochemical experiments. The results show that the change in the corrosion rate of the alloy after aging treatments at 170 and 230 ℃ is similar, and the corrosion rate firstly decreases and then increases, and finally reaches a stable value. However, the corrosion resistance of the alloy after aging treatment at 230 ℃ is much worse than that of the alloy after aging treatment at 170 ℃, and the time needed to reach the lowest corrosion rate is longer. In addition, the electrochemical corrosion behavior of the alloy after different aging treatments is similar, the corrosion potential has no obvious regularity, and the change tendency of corrosion current density and corrosion rate is almost identical. The corrosion rate decreases with the prolongation of corrosion time, and finally remains at a relatively stable value. Furthermore, the theoretically calculated values of corrosion rate are consistent with the measured values.