Recent demand on welding fluxes for high-strength low-alloy steel grades has necessitated the development of CaF₂-free fluxes towards high heat input applications. To meet such requirements, a flux design strategy has been postulated by varying MnO/(CaF₂ + MnO) mass ratio in the CaF₂–SiO₂–MnO flux system. The effect of MnO substitution for CaF₂ on the flux viscosity and structure has been investigated, and a quantitative relationship between viscosity and structural units has been put forward. In addition, it has been suggested that the degree of polymerization (DOP) of silicate network is reduced with increasing MnO/(CaF₂ + MnO) mass ratio, indicating MnO plays the role of network-breaker. The spectra of F_1s and ¹⁹F prove that F⁻ predominantly bonds with Ca²⁺ rather than Si⁴⁺, revealing CaF₂ acts as a diluent and does not effectively depolymerize the silicate network. Linear correlations can be obtained between the logarithm viscosity and the average non-bridging oxygen per silicon atom (NBO/Si), which can potentially be used as a DOP index to quantify the impact of silicate structure on the viscosity of the flux.

最近对高强度低合金钢等级的焊剂的需求使得有必要开发不含CaF ₂的焊剂以用于高热输入应用。为了满足这些要求，通过改变CaF ₂ -SiO ₂ -MnO 助熔剂系统中的 MnO/(CaF ₂  + MnO) 质量比来假设助熔剂设计策略。研究了MnO替代CaF ₂对助熔剂粘度和结构的影响，并提出了粘度和结构单元之间的定量关系。此外，有人提出，随着 MnO/(CaF _{2的增加，硅酸盐网络的聚合度 (DOP) 会降低。} + MnO) 质量比，说明 MnO 起断网作用。_{F 1s}和¹⁹ F的光谱证明 F ^-主要与 Ca ²⁺而不是 Si ⁴⁺键合，表明 CaF ₂充当稀释剂并且不能有效地解聚硅酸盐网络。可以在对数粘度和每个硅原子的平均非桥接氧 (NBO/Si) 之间获得线性相关性，这可以潜在地用作 DOP 指数来量化硅酸盐结构对焊剂粘度的影响。