Reduced susceptibility to stress-relief cracking in the CGHAZ by modifying grain boundary character

Influence of Microstructure Evolution on Reheat Cracking Behavior of T23 Steel Weld Joint

“…The strain-to-fracture (STF) test is an efficient method for quantifying the susceptibility to elevate temperature cracking. 6,7,10) After two thermal cycles, STF tests were subsequently performed with the same specimens on the Gleeble-3500. A preload of 100 MPa was applied to the specimen before the STF test.…”

Microstructure and Micro Strain in the CGHAZ of 2.25Cr-1.6W Steel after Intercritical Heat Treatment

“…Additionally, coarser precipitates formed at these high angle boundaries. 7) Therefore, the crack in the CGHAZ of 2.25Cr-1.6W steel tended to nucleate and propagate along these newly former recrystallized grain boundaries. As could be seen, the recrystallization increased the tortuosity of cracking path in both materials.…”

“…7) For Type Ⅰ, none of the newly formed grain boundaries overlap with the PAGBs. For Type Ⅱ, only a part of the newly formed grain boundaries overlap with the PAGBs.…”