What Is Resistance Spot Welding?

Resistance spot welding uses a spot welder to weld cross bars, which can be formed into a reinforced mesh or skeleton instead of manual binding. Compared with manual lashing, electric welding has the characteristics of high efficiency, labor saving, good integrity of the finished product, material saving, and cost reduction.

The working principle of spot welding is shown in the figure. Place the crossing part of the reinforcing bar between the two electrodes of the spot welder, and then apply electricity. The temperature of the reinforcing bar rises to a certain height and then melts. Then the pressure is applied to weld the reinforcing bars at the intersection.

The main working parameters of resistance spot welding include the number of transformer stages, welding energization time, current strength,

Rebar

The quality inspection of spot welded joints includes two parts: visual inspection and strength inspection. When sampling, the appearance inspection should be carried out in batches according to the same type of products. Generally, 5% for each batch of products; 10% for each batch of important products such as beams, trusses, etc. It is required that the metal at the solder joints be melted uniformly; the indentation depth meets the requirements; the solder joints do not fall off, miss welding, cracks, porosity defects and obvious burns; the product size and grid spacing deviation should meet relevant regulations. The deviation should meet the relevant regulations. During strength inspection, cut from each batch of finished products.

Hot-rolled rebar weld joints shall be subjected to shear tests; cold-drawn low-carbon steel wire weld joints shall be subjected to shear tests, as well as tensile tests for smaller wires. The strength index shall meet the requirements of the Rebar Welding and Acceptance Regulations. As a result of the test, if one test piece fails to meet the above requirements, a double number of test pieces shall be taken for re-inspection. As a result of the re-inspection, if there is still a test piece that fails to meet the above requirements, the batch of products is unqualified. After the reinforcement treatment, secondary acceptance can be performed ^[1] .