ABSTRACT

A dual-circulation testing system was constructed to study the effect of heat flux density (q, −22.28 ∼ +22.54 kW m^-2) on the corrosion of an Al–Cu–Mg–Mn alloy in 0.5 M H₂SO₄ at a constant metal surface temperature (50°C) under different controlling heat transfer states. Their heat transfer parameters were determined quantitatively by COMSOL simulation to keep them except q in constant, highlighting the influence of q on metal corrosion. Compared with the q = 0 condition, the positive heat flux (q > 0) improved the surface layer performance of the Al alloy to inhibit its anodic corrosion process, decreasing its corrosion current density (i_corr) by 56% with increasing q to 22.54 kW m^-2. While q < 0, the opposite effect occurred, increasing its i_corr by 52% at q = −22.28 kW m^-2. Heat flux also changed the corrosion reaction’s apparent effective activation energy (E_a) and pre-factor, and E_a played a dominating role in changing i_corr.

摘要

构建双循环测试系统以研究热流密度 ( q , −22.28 ∼ +22.54 kW m ^-2 ) 对 Al–Cu–Mg–Mn 合金在 0.5 MH ₂ SO ₄中腐蚀的影响在不同的控制传热状态下金属表面温度恒定（50°C）。它们的传热参数通过 COMSOL 模拟定量确定，以保持除q以外的参数恒定，突出q对金属腐蚀的影响。与q  = 0 条件相比，正热通量（q > 0) 改善了铝合金的表面层性能以抑制其阳极腐蚀过程，随着q增加到 22.54 kW m ^{-2 ，其腐蚀电流密度 (} i _corr ) 降低了 56% 。当q  < 0 时，会出现相反的效果，在q  = −22.28 kW m ^-2时将其i _corr增加 52% 。热通量还改变了腐蚀反应的表观有效活化能( E _a )和预因子，其中E _a对i _corr的变化起主导作用。