XU Chunhua, XIE Shuxian, WANG Hairui, et al. Effect of welding heat input on microstructure and properties of CGHAZ of ultra-low carbon bainitic steel[J]. 2021,51(2):37-40. DOI： 10.7512/j.issn.1001-2303.2021.02.06.
In order to explore the effect of different welding inputs on the microstructure and impact properties of coarse grain heat-affected zone（CGHAZ） of ultra-low carbon bainitic steel welded joint,Gleeble-3500 thermal simulation machine was used to simulate different inputs to study the effects of different heat inputs on the microstructure and impact toughness of CGHAZ of Q420 qEN steel joint. And the CGHAZ was characterized. The results show that as the welding heat input increases,the mic-rostructure of CGHAZ becomes coarser,the lath bainite decreases and granular bainite increases;meanwhile,when the welding heat input increases from 18 kJ/cm to 30 kJ/cm,the impact toughness of CGHAZ at-20℃ increases first and then decreases.