Resistance Spot Welding Workpiece Stack-Ups Having Steel Workpieces With Surface Coatings

A method of resistance spot welding a workpiece stack-up that comprises a first steel workpiece and a second steel workpiece, the method comprising:

• providing the first steel workpiece and providing the second steel workpiece, the first steel workpiece being composed of an advanced high-strength steel (AHSS) material and the second steel workpiece being composed of an advanced high-strength steel (AHSS) material, the first steel workpiece having a first faying surface and having a first exterior surface situated opposite the first faying surface, the second steel workpiece having a second faying surface and having a second exterior surface situated opposite the second faying surface, a first surface coating residing on the first exterior surface, and a second surface coating residing on the second exterior surface;
• layering a filler metal on the first faying surface of the first steel workpiece via additive manufacturing;
• bringing the second steel workpiece to the first steel workpiece, the second faying surface of the second steel workpiece adjoining the filler metal;
• clamping a first welding electrode and a second welding electrode on the first and second steel workpieces adjacent the filler metal;
• passing electrical current between the first and second welding electrodes;
• and
• terminating passage of the electrical current to establish a weld joint between the first and second steel workpieces.

A method of resistance spot welding a workpiece stack-up that comprises a first steel workpiece and a second steel workpiece, the method comprising:

• providing the first steel workpiece and providing the second steel workpiece, the first steel workpiece being composed of an advanced high-strength steel (AHSS) material and the second steel workpiece being composed of an advanced high-strength steel (AHSS) material, the first steel workpiece having a first faying surface and having a first exterior surface situated opposite the first faying surface, the second steel workpiece having a second faying surface and having a second exterior surface situated opposite the second faying surface, a first surface coating residing on the first exterior surface, and a second surface coating residing on the second exterior surface, the first surface coating being composed of a zinc (Zn) material and the second surface coating being composed of a zinc (Zn) material;
• layering a filler metal on the first faying surface of the first steel workpiece via additive manufacturing, the filler metal being composed of a low-carbon steel material;
• bringing the second steel workpiece to the first steel workpiece, the second faying surface of the second steel workpiece adjoining the filler metal;
• clamping a first welding electrode and a second welding electrode on the first and second steel workpieces adjacent the filler metal;
• passing electrical current between the first and second welding electrodes;
• and
• terminating passage of the electrical current to establish a weld joint between the first and second steel workpieces, the weld joint including material of the first steel workpiece and including material of the second steel workpiece and including material of the filler metal.