Analytical Study on Effects of Welding Deposition Sequence on Microstructure and Hardness in Beam-to-Column Welded Connection of Steel Framed Structures

—Studies on Relation between Joint Performance and Welding Heat Cycles in Welded Joints (Report 2)—

Abstract

Numerical simulation of temperature, mictostructure, and hardness is performed in multi-pass welded joints of beam-to-column connections of steel framed structure. The effects of temperature history on microstructure and hardness are investigated in this paper. Three-dimensional thermal elastic-plastic finite element analysis is performed by using the moving heat source and considering phase transformation effect. The relation between cooling rate and Vickers hardness in the weld metal is pigeonholed from the result of the simulation. Elapsed cooling time t_8/5 is effective to evaluate the hardness in the weld metal. Vickers hardness in heat-affected zone is also computed and well explained from heat cycles. It is found that tensile strength of the weld metal and the heat-affected zone might be predicted by numerical simulation.