The invention relates to a non-preheat
welding method of high-strength steel whose tensile strength 800MPa, wherein it comprises (1), the connector has V-shape slope
cut; (2), cleaning the slope before
welding; (3), using impulse
welding power source to weld in Ar+CO2
mixed gas or CO2 gas, while the welding
voltage is 30-34V, the welding current is 200-240A, the welding speed is 0.4cm / s-0.6cm / s, the welding heat input is 10kJ / cm-20kJ / cm, and the protect
gas flux is 15L / min-25L / min;(4), using 600MPa or 700MPa
drug welding or
solid welding wire to weld bottom, while other welding channels use 800MPa
drug welding wire to multilayer weld, without intermission; (5), using
alumina silicate plate to cover the welding head, to cool. The invention can avoid preheat and following
thermal treatment, with low cost, while the welding seam has high flexibility.