As fast cooling in the spot inherent in hardened steel hard and brittle martensite when the organization will be larger in the stress cracks. In order to eliminate quenching to improve the joint performance, usually tempered after welding0 electrode   double pulse spot welding consumable  , which the first current pulse to pulse welding, the second pulse for the tempering, the use of this method should note two points:

(1) the time interval between the two pulses must be cooled to ensure that the spot temperature below the martensitic transformation point Ms;

(2) tempering current pulse amplitude should be appropriate to avoid the welding area of ??the metal back more than Austenite caused by secondary quenching.

keywords: Aluminum Electrode