A resistance spot welding method is disclosed for joining two or more steel sheets including at least one steel sheet having a tensile strength of 980 MPa or higher. The resistance spot welding method involves placing the steel sheets on top of each other to form a set of steel sheets to be welded, clamping the set of steel sheets with a pair of electrodes, and passing a current through the steel sheets while applying pressure thereto to join the steel sheets together. The resistance spot welding method includes an initial welding step of welding by passing a current I1 (kA) satisfying 2×√F1<I1≤10×√F1 while applying a welding force F1 (kN) satisfying 0.2×√t1<F1≤4×√t1, and a main welding step of forming a nugget having a predetermined nugget diameter. Spatter is produced in the initial welding step.

This disclosure relates to weldability of steel alloys that provide weld joints which retain hardness values in a heat affected zone adjacent to a fusion zone and which also have improved resistance to liquid metal embrittlement due to the presence of zinc coatings.

An intrinsic process signal-based online expulsion detection method for resistance spot welding process, which comprises: acquiring the intrinsic process signal and current signal output by sensors installed at two electrodes in real-time during the welding process and establishing a relationship graph; performing expulsion judgement based on the relationship graph to obtain expulsion frequency, single intrinsic process signal feature and an accumulated feature; calculating expulsion metal volume according to the accumulated feature and electrode profile features to obtain a prediction expulsion metal amount. The method performs online prediction of the expulsion metal amount according to the intrinsic process signal for resistance spot welding process, thereby achieving online quantitative estimation of the expulsion intensity, overcoming the defect of the traditional technology which relies on manual detection, and improving detection efficiency and accuracy.

Method for welding two stainless steel sheets of thickness (e) 0.10 to 6.0 mm and having a particular composition having: a first welding step lasting a time (t) in ms: 0.10 to 0.50 mm, t=(40×e+36)±10%; 0.51 to 1.50 mm: t=(124×e 13)±10%; 1.51 to 6.0 mm: t=(12×e+47)±10%; with clamping force (F) in daN: 0.10 to 1.50 mm: F=(250×e+90)±10%; 1.51 mm to 6.0 mm: F=(180×e+150)±10%; appling a current between the welding electrodes, of intensity between 80 and 100% the maximum permissible intensity corresponding to expulsion of molten metal; a second step with an intensity between zero and 1 kA; and a third step with an intensity of 3.5 kA to 4.5 kA, for a time of at least 755 ms.

A method for providing a component assembly for a motor vehicle includes inserting a weldable element into an opening of a first metal sheet such that a joint is defined between the weldable element and the first metal sheet and such that a reservoir connected to the joint is preserved at a first side of the first metal sheet that faces a second metal sheet where the reservoir is open in a direction toward the second metal sheet. The method further includes applying an adhesive to the first side of the first metal sheet and/or to the second metal sheet and placing the second metal sheet against the first metal sheet and the weldable element and welding the second metal sheet to the weldable element.

A method for electric welding a workpiece arrangement having at least one workpiece with the aid of a robot arrangement including at least one robot. A rotational movement is carried out between the workpiece arrangement to be welded and at least one welding electrode which contacts the workpiece arrangement. The rotational movement is started as a function of a commanded and/or detected welding start and/or ended as a function of a commanded and/or detected welding end. The direction of rotation of the movement may be changed as a function of a predefined parameter during contact between the welding electrode and the workpiece arrangement.

Rivet dispenser systems and methods of use thereof are provided. In a non-limiting embodiment, the rivet dispenser system comprises a rivet receiving member defining a channel therein, and a seat member. The channel includes a curved region. The rivet receiving member comprises a first port and a second port. The first port communicates with the channel and is configured to receive rivets. The second port communicates with the channel and is configured to dispense rivets. The channel extends between the first port and the second port and is configured to transport rivets from the first port to the second port in a series arrangement and in a preselected orientation. The seat member communicates with the second port and is configured to selectively engage with a rivet holder of a resistance spot rivet welding apparatus and introduce a single rivet to the rivet holder at one time.

A resistance welder controller controls a welding current flowing through an inverter transformer, detects the welding current flowing through the inverter transformer, measures an energizing time and a point time interval of the detected welding current, calculates a usage rate of the inverter transformer using the energizing time and the point time interval, stores an equivalent current curve indicating a relationship between a current value of the welding current and the usage rate of the inverter transformer when the inverter transformer is operated at a rated capacity, and determines whether a relationship between the current value and the calculated usage rate of the inverter transformer exceeds the rated capacity of the inverter transformer based on the equivalent current curve, continues an operation when the relationship does not exceed the rated capacity of the inverter transformer, and stops the operation when the relationship exceeds the rated capacity of the inverter transformer.

A combined stackup apparatus with a perforated interlayer for resistance spot welding is provided. The apparatus comprises a first metal sheet of a first material and a second metal sheet of a second material. The apparatus further comprising a perforated interlayer disposed between the first metal layer and the second metal layer. The perforated interlayer is made of one of the first and second materials. The perforated interlayer has a plurality of perforations formed therethrough. Each perforation has a perforation size of between about 0.1 mm and about 3 mm.

Provided is a resistance spot welding method wherein main current passage includes two or more electrode force application steps including a first electrode force application step and a second electrode force application step following the first electrode force application step, an electrode force F.sub.1 in the first electrode force application step and an electrode force F.sub.2 in the second electrode force application step in the main current passage satisfy a relationship F.sub.1<F.sub.2, and an electrode force switching point T.sub.f from the first electrode force application step to the second electrode force application step in the main current passage is set to satisfy predetermined relational formulas.