Smelting flux for welding HSLA steel and preparation method thereof

The invention relates to the technical field of welding, and particularly relates to a smelting flux for welding HSLA steel and a preparation method thereof. The smelting flux for welding the HSLA steel comprises the following components in percentage by mass: 50-65% of CaF2, 18-28% of ZrO2 and 17-23% of SiO2. The welding method is submerged-arc welding. The smelting flux is added with higher content of ZrO2, and is cooperated with CaF2 and SiO2 for welding specific types of steel, so that welding lines are excellent in low-temperature toughness, tensile strength and slag removing performance, excellent in arc stabilizing performance and welding line forming performance and stable in welding process; and the welding lines obtained after welding are uniform in metal components and structures, excellent in surface appearance and free of such defects as air holes and cracks. 本发明涉及焊接技术领域，具体而言，涉及一种用于焊接HSLA钢的熔炼焊剂及其制备方法。用于焊接HSLA钢的熔炼焊剂包括按照质量百分比计的如下组分：CaF250%~65%，ZrO218%~28%和SiO217%~23%；所述焊接的方法为埋弧焊。该熔炼焊剂通过加入较高含量的ZrO2，