I Hajiannia - Department of Materials Engineering, Isfahan University of Technology, Isfahan ۸۴۱۵۶-۸۳۱۱۱, Iran
M Shamanian - Department of Materials Engineering, Isfahan University of Technology, Isfahan ۸۴۱۵۶-۸۳۱۱۱, Iran
M Atapour - Department of Materials Engineering, Isfahan University of Technology, Isfahan ۸۴۱۵۶-۸۳۱۱۱, Iran

Resistance spot welds were produced in of advanced high strength Steel, TRIP steel. The microstructure and mechanical properties were characterised using metallurgical techniques, lap shear and microhardness testing respectivly. The results shown that a pullout failure mode with improved mechanical properties is obtained when current is 10kA with 4kN. Mechanical properties have been Relationship between the sizes of nugget with force. Results also indicated that despite the similarity of both current, the sample with greater force has significantly larger nugget size and the maximum force is larger. Result of microhardness was shown TRIP980 weld has been a harder fusion zone than the HAZ. Also the softening was caused by increased martensite was tempering through the HAZ approached the weld

TRIP steel, Resistance spot welds, mechanical properties, microstructure