C.S. Wu
金属学报(英文版)
Realizing of weld penetration control in gas tungsten arc welding requires establishment of a model describing the relationship between the front-side geometrical parameters of weld pool and the back-side weld width with sufficient accuracy. A neural network model is developed to attain this aim. Welding experiments are conducted to obtain the training data set (including 973 groups of geometrical parameters of the weld pool and back-side weld width) and the verifying data set (108 groups). Two data sets are used for training and verifying the neural network, respectively. The testing results show that the model has sufficient accuracy and can meet the requirements of weld penetration control.
关键词:
C.S. Wu
,
J.Q. Gao
金属学报(英文版)
The anode region of welding arc is divided into three subzones: the anode boundary layer, the presheath and the sheath. A model is established for analyzing the transport mechanisms in the anode boundary layer. The computer program is designed and the governing equations of the dominating processes with the boundary conditions taken from the solutions of LTE plasmas are solved by applying the Runge-Kutta procedure.One parameter θ, the ratio of the heavy particle temperature at the free-fall edge to the anode surface temperature, is introduced into this study. The results indicate that when the parameter θ is of the value 6 the predicted heat flux at the anode surface matches the measured one. Based on the model, various plasma properties in the boundary layer can be obtained. The calculated results are in good agreement with the measurements.
关键词:
welding arc
,
null
,
null
C.S. Wu
,
Z. Zhang
,
F.H. Cao
金属学报(英文版)
The influence of chloride or sulphur dioxide on the corrosion behavior of copper tube
in the air-conditioning system was studied using scanning electron microscope (SEM),
energy dispersion spectrometer (EDS) and cyclic polarization techniques. The results
showed that the corrosion of copper tube are mainly caused by the SO4 and Cl ions
in the circulating water, and the former is mainly responsible for the general corrosion
of the copper tube whilst the latter for the pitting corrosion. The di®erent in°uences
of SO4 and Cl ions on the corrosion type of copper tube may be attributed to that
the radius of SO4 ion is much larger than that of Cl ion. Meanwhile the results
also indicated that SO4 inhibits the pitting corrosion caused by Cl and Cl inhibits
the general corrosion initiated by SO4 due to their competitive adsorption on the
copper matrix.
关键词:
copper
,
null
,
null
