脉冲电压对消火栓用铝镁铜合金耐热腐蚀性能的影响

Effect of Pulse Voltage on the Corrosion Resistance of Al-Mg-Cu Alloy for Fire Hydrant

为提高消火栓用Al-3.2Mg-0.8Cu合金的耐热腐蚀性能,通过在其凝固时施加脉冲磁场方式来改变其组织性能,并通过试验测试研究了脉冲电压对其组织及耐热腐蚀性能的影响。研究结果表明:不同脉冲磁场条件下合金组织都形成了α-Al和Al 2Cu两相。随着脉冲电压的升高,第二相比例不断降低,合金试样表现出更优耐腐蚀性。在150 V电压下制得的合金试样达到了27.1 mm·a-1的低腐蚀速度,相对于无磁场条件试样表现出更强耐腐蚀性能。无磁场条件下的合金在热腐蚀过程中生成许多大尺寸腐蚀坑。当脉冲电压提高后,热腐蚀坑的深度与横向尺寸都开始变小,表现出了更优耐腐蚀能力。

In order to improve the heat-resistant corrosion performance of Al-3.2Mg-0.8Cu alloy used in fire hydrant,the internal structure performance was changed by applying pulsed magnetic field treatment during the solidification process,and the influence of pulsed voltage on the microstructure and heat-resistant corrosion performance was studied by experimental test.The results show thatα-Al and Al 2Cu are formed in the alloy under different pulsed magnetic field.The second phase ratio decreases with the increase of pulse voltage.With the increase of pulse voltage,the alloy sample showed better corrosion resistance.The alloy sample prepared at a voltage of 150 V reached a low corrosion rate of 27.1 mm·a-1,showing stronger corrosion resistance than the sample without magnetic field.Many large pits are formed during thermal corrosion of alloys without magnetic field.When the pulse voltage is increased,the depth and transverse size of thermal corrosion pits begin to decrease,showing better corrosion resistance.