气体渗碳动力学的研究

Study of the Kinetic of Gas Carburization

研究了925℃时,在实际渗碳气氛中的渗碳速度。建立了以CO解离吸附与氧脱附为基础的气体渗碳动力学模型。试验结果表明,在给定的渗碳气氛中,表面存在一个临界氧覆盖率θ0,当表面的氧覆盖率θ0小于θ0时,控制渗碳速度的是CO的解离吸附,当表面的氧覆盖率θ0大于氧临界覆盖率θ0时,渗碳速度由氧的脱附所决定。

The rates of gas carburization in practical atmospheres have been investigated at 925℃.The rate equations,which best described the experimental data,were based on a mechanism which involves dissociative adsorption of CO followed by desorption of adsorbed oxygen.The results indicated that there was a critical coverage of adsorbed oxygen θ  0 in a given atmosphere.When the real coverage of oxygen θ 0 is smaller than θ  0,the rate controlling step is the dissociative adsorption of CO.When θ 0 is greater than θ  0,the rate is controlled by the desorption of oxygen.