Laser-MAG hybrid transverse welding for backing weld of X80 pipeline steel in horizontal position

Taking X80 petroleum pipeline steel as the research object, the mechanical properties of laser-MAG hybrid transverse welded joint were evaluated by tensile test, bending test and hardness test. The influence of laser-wire spacing on the weld formation of laser-MAG hybrid transverse welding was studied. The results showed that the best weld symmetry was obtained when the difference between laser and wires was 2 mm, the coupling performance of the hybrid heat source was the best, and the downward flow tendency of the weld pool was the smallest. Results of the tensile test, bending test and microhardness test of X80 pipeline steel welded joints met the requirements of API 5 L standard.