Research on microstructure and performance of welded joints of HSLA steel under vibration conditioning

To study the effects of mechanical vibration on HSLA steel welded joints, Ar+CO₂ mixed gas was applied to shield the weld crater, mechanical vibration was applied at the same time. The results showed that vibration welding can improve weld metal microstructure, and can improve the weld metal impact energy to a certain extent. When the amplitude remain unchanged, the impact performance of weld joints is not sensitive to the vibration frequency and the effect of vibration on toughness only exists in a range of test temperature. With the test temperature reducing, the effect of vibration is weakened, when the test temperature reduce to a certain value, the vibration influence on toughness of welded joint will disappear.