A Study of Gas Metal Arc Welding of Low Carbon High Manganese Microalloyed Steels

摘要

1. The increase in Mn content from 2 to 4.5% caused to an increase in cold cracking susceptibility. 2. Crack initiation occurred in the weld metal at the weld toe, likely related to the segregation of alloying elements to the light etched strip adjacent to the fusion boundary in the weld metal. 3. Crack propagation in the coarse grained HAZ occurs along the prior austenite grain boundaries where alloying element segregation provides easy propgation paths. 4. No correlation was obtained between HAZ hardness and cold cracking in the steels studied. 5. The welds made at the highest heat input of 1.5 kJ/mm did not show any cracking (except for one). It is likely that further increase in the level of heat input of GMAW for these steels would eliminate cracking.