弯曲载荷作用下薄板的金属尘化腐蚀模型

基于Fick扩散第二定律及扩散热力学,推导得到扩散和外载荷因素耦合作用下的扩散方程,并以薄板为对象,差分求解得到尘化腐蚀过程中不同σ珟ho值时基于2种扩散模型内部瞬时碳浓度分布图,通过Cr5Mo钢的尘化腐蚀试验数据进行验证,理论计算与试验结果的一致性表明:推导得到的M-Fick2模型可描述载荷作用下金属尘化腐蚀扩散过程;弯曲载荷作用下,M-Fick2中修正项系数σ珟ho值越大,对扩散的影响也就越大;在弯曲载荷作用下,对扩散除了具有加速的作用外,还包括抑制的作用,当σ珟ho≤0.01时对扩散的加速作用和抑制作用都不显著。

Metal dusting corrosion model for thin plate on bending load

Based on Fick second law and diffusion thermodynamics,the diffusion equation was obtained considering the coupling effect of diffusion and external loads.According to dusting corrosion experiment of Cr5Mo steel,the carbon concentration distribution in thin plate on different factors ho≤0.01 could be obtained by a differential method based on two diffusion models in the process of metal dusting.The effect of chemical reaction in diffusion was also analyzed.The consistency of simulation and experimental results showed that the modified M-Fick2 model could describe the diffusion process of metal dusting corrosion with the applied bending load.The bending load had on important influence on the diffusion,the greater its value was.The greater the impact on diffnsion was;the bending load could play a role of acceleration and inhibition in diffusion.The effect on the bending load was not siginficant when ho≤0.01.