Method, device, apparatus and storage media for welding quality detection

A method for welding quality detection, applied on a welding device, said welding device having an operating process comprising a welding phase and a cooling phase after stopping welding current, the method comprising:

• applying a detection voltage to a weld for a period from the cut-off of the welding current until a temperature of the weld reaches a predetermined threshold;
• obtaining a detection current generated by the detection voltage applied to the weld;
• calculating resistances of the weld continuously varying during the cooling phase based on the detection voltage and the detection current;
• and
• determining whether a welding defect exists at the weld based on a trend of the variation of the resistances or on a comparison of the resistances with resistances of the qualified weld, comprising:
• determining there is an insufficient weld joint if, an initial value of the resistances of the weld is smaller than an initial value of the resistances of the qualified weld, a rate of decline of an intermediate value of the resistances of the weld is smaller than the rate of decline of the intermediate value of the resistances of the qualified weld, an end value of the resistances of the weld is larger than the end value of the resistances of the qualified weld, and a difference between the initial value of the resistances of the weld and the end value of the resistances of the weld is smaller than a first threshold.