The complete resistance spot weld cycle has been divided into ____ parts.

Explanation

Explanation: Resistance spot welding occurs in four steps. They are as follows: Squeeze time: The time required for the electrodes to align and clamp the work-piece together and provide necessary electrical contact. Weld time: Time the current flows through the work-piece till they are heated to melting temperature. Hold time: Time till the pressure is maintained, without the current, wherein the pieces are expected to get forge weld. Off time: When the pressure of the electrode is taken off so that plates can be positioned for the next spot. Resistance welding: This process makes use of the electrical resistance for generating heat that is required for melting the work-piece. Generally used to and join thin plate structures . Also considered as a green process since it does not generate gases and flames as in metal arc welding and gas welding. The heat generated in Resistance welding is given by H = I 2Rt H = Heat generated, I = Current, R = Resistance of joint, t = Time of flow of current. Resistance depends upon: work-piece to be joined electrode used gap resistance Types: Spot welding Individual weld is produced by momentary application of pressure and resistance into the work-piece. Seam welding It can produce continuous fast and leak-proof weld mainly used for thin metallic sheets, galvanized roofing, small tanks, etc Projection welding A dimple is embossed into one of the work-piece at the locations where the weld is desired.