The weldability of 12MnNiVR was examined in terms of the simulated HAZ continuous cooling transformation (SH-CCT) diagram,microstructure and mechanical properties of the simulated coarse grain heat-affected zone (CGHA...The weldability of 12MnNiVR was examined in terms of the simulated HAZ continuous cooling transformation (SH-CCT) diagram,microstructure and mechanical properties of the simulated coarse grain heat-affected zone (CGHAZ).When t 8/5 is shorter,the microstructure mainly consists of lath bainite.When t 8/5 is 60 s,the microstructure becomes coarser bainite.Some acicular ferrite appears beside lath bainite when t 8/5 =100s.Finally,a microstructure composed of polygonal ferrite,acicular ferrite,and small amount pearlite is obtained with a small amount of bainite at t 8/5 】100s.With the increase of t 8/5,the hardness of CGHAZ decreases considerably.The minimum impact toughness of CGHAZ appears at t 8/5 =100s.The hardness and the toughness of CGHAZ remain above the specified values for steel 12MnNiVR.展开更多
文摘The weldability of 12MnNiVR was examined in terms of the simulated HAZ continuous cooling transformation (SH-CCT) diagram,microstructure and mechanical properties of the simulated coarse grain heat-affected zone (CGHAZ).When t 8/5 is shorter,the microstructure mainly consists of lath bainite.When t 8/5 is 60 s,the microstructure becomes coarser bainite.Some acicular ferrite appears beside lath bainite when t 8/5 =100s.Finally,a microstructure composed of polygonal ferrite,acicular ferrite,and small amount pearlite is obtained with a small amount of bainite at t 8/5 】100s.With the increase of t 8/5,the hardness of CGHAZ decreases considerably.The minimum impact toughness of CGHAZ appears at t 8/5 =100s.The hardness and the toughness of CGHAZ remain above the specified values for steel 12MnNiVR.
