車身板腐蝕性能的影響
(鄭州大學(xué) 材料工程學(xué)院， 鄭州 450002)
摘 要: 采用全浸腐蝕實(shí)驗(yàn)、 鹽霧實(shí)驗(yàn)和電化學(xué)實(shí)驗(yàn)研究了微量元素Sr對(duì)Al-Mg-Si-Cu合金車身板腐蝕性能的影響。 全浸腐蝕實(shí)驗(yàn)結(jié)果表明： 合金加入Sr后， 其質(zhì)量損失速度由2.76 mg/(h·cm2) 降為1.39 mg/(h·cm2)， 鹽霧實(shí)驗(yàn)結(jié)果表明： 合金加入Sr后， 其質(zhì)量損失速度由8.56×10-3 mg/(h·cm2) 降為5.90×10-3 mg/(h·cm2)， Sr可以明顯減緩合金的腐蝕速度。 電化學(xué)實(shí)驗(yàn)結(jié)果表明： 合金加入Sr后， 合金穩(wěn)定電位較負(fù)， 穩(wěn)定時(shí)間長， 合金鈍化區(qū)較短， 腐蝕電位φcorr更負(fù)， 且腐蝕電流密度較小。
關(guān)鍵字: Al-Mg-Si-Cu基合金； 車身板； Sr； 腐蝕性能
alloy auto sheets
（ School of Materials Engineering, Zhengzhou University,
Zhengzhou 450002, China）
Abstract: The effect of microelement Sr on the corrosion properties of Al-Mg-Si-Cu based alloy auto sheets was studied by means of immersion corrosion, salt spray corrosion and electrochemistry test. The results of immersion tests show that the rate of mass loss is depressed from 2.76 to 1.39 mg/(h·cm2) when Sr is added into the alloy and the rate of mass loss is depressed from 8.56×10-3 to 5.90×10-3 mg/(h·cm2) in salt spray tests. Sr can minish the corrosion rate of the alloy obviously. The results of electrochemistry tests show that when Sr is added into alloy, the steady voltage of alloy is more negative, the steady time is prolonged, the passivation area of alloy becomes shorter, φcorr is negative and the density of corrosion current becomes smaller.
Key words: Al-Mg-Si-Cu based alloy; auto sheet; strontium; corrosion property
