Resistance welding device and resistance welding method

A resistance welding device for welding multiple stacked welding target members of a workpiece by pressurizing the workpiece in a stacking direction while supplying power to the workpiece, the resistance welding device comprising:

• a first electrode located on a first side in the stacking direction with respect to the workpiece and having a first contact surface in contact with the workpiece;
• and
• a second electrode located on a second side in the stacking direction with respect to the workpiece, having a second contact surface in contact with the workpiece, and sandwiching the workpiece together with the first electrode,
• the first electrode having, at part of the first contact surface, a first reduction portion configured to reduce sinking into the workpiece during power supply,
• the second electrode having, at part of the second contact surface, a second reduction portion configured to reduce sinking into the workpiece during power supply.

A resistance welding method for welding, using a first electrode and a second electrode, multiple stacked welding target members of a workpiece by pressurizing the workpiece in a stacking direction while supplying power to the workpiece,

• the first electrode having a first contact surface that is in contact with the workpiece and includes at least one first overlapping portion and at least one first non-overlapping portion,
• the second electrode having a second contact surface that is in contact with the workpiece and includes at least one second overlapping portion and at least one second non-overlapping portion,
• the first overlapping portion and the second overlapping portion overlapping with each other in the stacking direction, the first non-overlapping portion and the second non-overlapping portion not overlapping with each other in the stacking direction, the resistance welding method comprising:
• pressurizing the workpiece in the stacking direction with the first overlapping portion and the second overlapping portion;
• and
• supplying power to the workpiece with at least the first non-overlapping portion and the second non-overlapping portion.