Assessment of the Heat Input Effect on the Distribution of Temperature Cycles in the HAZ of S460MC Welds in MAG Welding

Abstract

Temperature cycles generated during welding have a significant effect on the changes in the HAZ of welds, regardless of whether these are changes in structure or mechanical properties; however, it is problematic to obtain temperature cycles with sufficient accuracy across the entire HAZ so that they can be generally taken and used in welding simulations and for real experiments of processes occurring in HAZ. In particular, for a study in a specific location, it is important to know the maximum temperature of the cycle and the cooling rate defined mainly by the parameter t8/5. No studies in which anybody tries to find a mathematical description defining the basic parameters of temperature cycles in the HAZ could be found in the performed research. Therefore, the study presented in this paper results in a mathematical description defining the dependence of achieved maximum temperature on the distance from the fusion line in the HAZ of S460MC welds and with heat input values in the interval from 8 to 14 kJ·cm−1. Moreover, this paper presents the influence of heat input value on the weld pool geometry, including the effect of heat input value on grain coarsening in the highly heated HAZ.