TY  - EJOU
AU  - Gan, Lifeng 
AU  - Zhu, Baoyin 
AU  - Ling, Chao 
AU  - Busso, Esteban	P. 
AU  - Li, Dongfeng 

TI  - Micromechanical	Study	of	Heterogenous	Deformation	of	Austenitic	 Stainless	Steel	Welded	Joints	at	Different	Temperatures
T2  - The International Conference on Computational \& Experimental Engineering and Sciences

PY  - 2023
VL  - 25
IS  - 3
SN  - 1933-2815

AB  - Heat-resistant	austenitic	stainless	steels	are	widely	used	in	the	final	stages	of	superheater	and	reheater	in	
in	 the	new	generation	of	 fossil	 fuel	power	stations,	due	 to	 their	high	creep	strength.	Similar	weld	joints,	
fabricated	using	gas	tungsten	arc	welding,	for	connecting	different	components	made	of	the	heat	resistant	
austenitic	stainless	steels	usually	suffer	from	premature	failures	at	elevated	temperature	[1].	Experimental	
studies	showed	that	cracks	may	nucleate	in	the	heat	affected	zone	or	weld	metal of	the	similar	welded	joints	
under	service	conditions.	In	order	to	reveal	the	physical	origin	of	unexpected	failures	of	the	weld	joints,	a	
microstructure-based	modelling	work	has	been	performed.	Firstly,	the	microstructure	of	the	welded	joints	
was	 experimentally	 characterised,	 and	 then	 a	 representative	 weld	 microstructure	 model	 was	 digitally	
reconstructed	using	Electron-Back-Scattered	Diffraction	(EBSD)	and	finite	element	techniques.	The	stressstrain	behaviour	of	each	weld	region	at	different	temperatures was	identified	using	a	combination	of	digital	
image	correlation	(DIC)	techniques,	uniaxial	tensile	and	microindentation	tests.	Dislocation	density-based	
crystal	plasticity	models	[2]	are	then	formulated	and	calibrated	so	as	to	describe	the	behaviour	of	each	weld	
region.	 Crystal	 plasticity	 finite	 element	 simulations	 were	 carried	 out	 based	 on	 the	 generated	 weld	
microstructure	model	to	study	the	heterogenous	distribution	of	stress	and	strain	at	the	grain	level.	Local	
damage	initiation	mechanisms	were	systematically	analysed	for	different	weld	regions.
KW  - Weld	joints;	austenitic	stainless	steel;	digital	image	correlation;	crystal	plasticity

DO  - 10.32604/icces.2023.010397