高强度铝合金中氢传输的研究

采用化学镀镍层作为铝合金LC4上防护层,应用电化学氢渗透技术研究了氢在LC4中的静态传输规律以及在不同热处理状态下,氢在LC4中的传输对其应力腐蚀敏感性的影响。实验结果表明:常温下氢在LC4中的静态传输是以扩散为控制步骤的过程。氢扩散系数为10~(-9)cm~2·s~(-1)数量级,为同条件下氢在纯铝中扩散系数的四分之一;LC4材料的DCB试样在常温下的3.5％NaCl溶液中的应力腐蚀断裂不遵循氢脆机理。

THE STUDY OF HYDROGEN TRANSPORT IN HIGH STRENGTH ALUMINUM ALLOY LC4

A protection film of high strength aluminum alloy LC4 was obtained by means of electroless neck-el coating. Using clectrochemical hydrogen permeation technique,the static transport law of hydrogen in LC4 was investigated and the effect of hydrogen transport on the SCC susceptibility of LC4 under two different heat treatment conditions was studied. Results indicate that the rate-determining step of the static transport of hydrogen in LC4 at ambient temperature is the diffusion process and the order of magnitude of hydrogen diffusion coefficient is 10-9cm2 . s-1(1/4 times that in pure aluminum). The SCC of DCB specimens of LC4 in 3. 5% NaCl solution at room temperature does not follow the hydrogen embrittlement mechanism.