The Effects of Temperature during Post-heating Treatment on Residual Stress of Resistance Spot Welded High-strength Steel Sheets

Abstract

This study investigates the effects of maximum temperature and temperature history during post-heating treatment on residual stress of resistance spot welded high-strength steel sheets. To examine the effects of post-heating treatment, numerical simulations were performed. First, the effect of the phase proportion of tempered martensite and maximum temperature was investigated. This result shows that both of the phase proportion of tempered martensite and maximum temperature affect the residual stress. Second, only the effect of the maximum temperature was examined when the almost all martensite changed to tempered martensite. This result shows that the low maximum temperature decreases the residual stress. Finally, as an example, controlling the temperature history was proposed to satisfy both of the controlling the residual stress and shortening the tempering time. This result shows that controlling temperature history can decrease the maximum temperature in short tempering time and control the tensile residual stress.