AZ61A镁合金搅拌摩擦焊接头在NaCl溶液中的腐蚀行为(英文)

对6mm厚的挤压态AZ61A镁合金板进行搅拌摩擦对接焊。采用浸泡试验研究焊接接头在NaCl溶液中的腐蚀行为,建立了一个经验公式来预测在不同的溶液pH值、浸泡时间和氯离子浓度下的接头腐蚀速率。该经验公式的可信度水平为95%。采用3因素、5水平的中央复合旋转设计方法来减少实验工作量。采用响应面方法来构建方程。结果表明,在碱性溶液中AZ61A镁合金接头的腐蚀速率要比其在酸性或中性溶液中的低,而且腐蚀速率随着氯离子浓度的降低和浸泡时间的延长而减少。β相的分布对其腐蚀形貌有重要影响。

Corrosion behaviour of friction stir welded AZ61A magnesium alloy welds immersed in NaCl solutions

The extruded AZ61A magnesium alloy plates of 6 mm thickness were butt welded using friction stir welding(FSW) process.The corrosion behavior of the welds was evaluated by conducting immersion test in NaCl solution at different pH value,immersion time and chloride ion concentrations.An empirical relationship was established incorporating pH value,immersion time and chloride ion concentration to predict the corrosion rate of friction stir welds of AZ61A magnesium alloy at 95% confidence level.Three-factor,five-level central composite rotatable design was used to minimize the number of experimental conditions.Response surface method was used to develop the relationship.The results show that the corrosion resistance of AZ61A magnesium alloy welds in the alkaline solution is better than that in the acidic and neutral solutions,moreover,low corrosion rate is found at low concentrated solution and longer exposure time,and the corrosion morphology is predominantly influenced by the distribution of β-phase.