SPOT WELDED JOINT AND SPOT WELDING METHOD Russian patent published in 2018 - IPC B23K11/10 

FIELD: metallurgy.

SUBSTANCE: invention can be used for contact spot welding of sheets of high-strength steel, particularly in the automotive industry. Welded joint obtained by spot welding contains not less than 375 crystalline grains of crystallized structures in the region of 0.5 mm × 0.5 mm at the edge of the core of the welded point. In implementation of the method, the step of creating a melt zone by passing the current and a step of crystallizing the melt zone with the supply of current are carried out, lower than the current used during creation of the melt zone. At crystallization stage, electromagnetic vibration is applied to the melt zone. Frequency f_V electromagnetic vibration, the velocity ν_S crystallization of the melt zone and the inter-axial distance λ_D branches of dendrites during crystallization of the melt zone satisfy the condition 0.2 ≤ ν_S / (λ_D ⋅ f_V) ≤ 4.0.

EFFECT: invention provides a high toughness of weld metal and strength of a spot welded joint.

3 cl, 7 dwg, 1 ex, 3 tbl