The invention discloses a
laser-MAG (
Metal-Active-Gas) compound
welding method used for
welding and splicing high-strength or ultrahigh-strength steel of a
thick plate. The method aims at high-strength or ultrahigh-strength steel thick plates and utilizes a
laser-MAG compound heat source to carry out single-side single-channel, single-layer and double-face molding
welding; a welding part is an I-shaped groove;
laser or oxyacetylene
torch is adopted to pre-heat a work-piece before welding; and the temperature is kept for 20 min to 1 hour after the welding. The welding technical parameters are that the spot
diameter of the laser is 0.3-1 mm, the laser power is 4-10 KW, the arc current is 200-300 A, and the
arc voltage is 25.2-30 V. By improving the form of the groove of the work-piece and reserving an assembling distance and optimized welding parameters during the splicing, the splicing and welding of the ultrahigh-strength steel plate is realized; the welded joint performance is satisfied with and better than that of regular TIG (
Tungsten-
Inert-Gas) welding, the welding speed can be up to 60 m / h; and the welding efficiency is improved by 10 times than the regular TIG welding.