The shape of a DC electric arc in arc welding with monoatomic shielding gases (Ar, He and Ar/He blends) is generalized in dimensionless form with algebraic correlations. The novel expressions capture the main magnetohydrodynamic arc characteristics (temperature, velocity, magnetic field) and also yield the main arc–weld-pool interactions (heat flux, current density and pressure). The proposed correlations are validated against numerical results presented in this work and numerical and experimental results found in the literature. Simulated electric arcs conditions considered include arc currents and arc lengths in the range of 200–300 A and 5–10 mm respectively, burning in Ar and Ar-He mixtures and arc lengths ranging from 7–10 mm for He.

用单原子保护气体（Ar，He和Ar / He混合气体）进行电弧焊时的直流电弧形状具有无量纲形式，具有代数相关性。这些新颖的表达式捕捉了主要的磁流体动力电弧特性（温度，速度，磁场），还产生了主要的电弧-焊池相互作用（热通量，电流密度和压力）。相对于这项工作中提出的数值结果以及文献中发现的数值和实验结果，验证了所提出的相关性。考虑的模拟电弧条件包括：电弧电流和电弧长度分别在200–300 A和5–10 mm范围内，在Ar和Ar-He混合物中燃烧，He的电弧长度在7–10 mm范围内。