Investigation on mechanical properties and microstructure evolution of DP steel TWBs

To understand the effect of process parameters on the mechanical properties and microstructure evolution of dual-phase(DP) steel tailor welded blanks(TWBs) during warm deforming,the warm tensile tests at different temperatures and strain rates were carried out.The mechanical properties and microstructure evolution of DP590 steel TWBs during warm tensile tests were influenced by temperature and strain rate,and all of those factors were reflected by Zener-Hollomon(Z) parameter.The results indicated that at the range of given experimental Z parameter,due to the dynamic recrystallization,the lower the Z parameter,the lower the stress-strain curves,and as Z parameter decreased,the elongation at fracture,the volume fraction of recrystallization and average grain size increased.