Influence of the ferrite rate on the tenacity of a welded joint in austenitic stainless steel: Experimental study and numerical modelling

This work is about the experimental and numerical study of the global mechanical behavior of a welded joint using TIG welding process (tungsten inert gas) of austenitic stainless steels 316L. Generally, the mechanical properties characteristics of this type of welded joint depend mainly on two parameters: the quality of weld metal and the quality of gaseous protection. qualities of molten metal: (UP-CNM 18 16), (SG-X2/CNM 19 12) and (SG-X12/CNM 19 10) were used. On each of the configurations, mechanical tests of characterization were carried out: tensile test, impact strength, rupture and of folding. In order to simulate the holding of corrosion of the weld, the specimens were emerged in a device corrosion test during one week. servation made and the results obtained from different mechanical tests had been correlated in order to propose for welding of austenitic stainless steels 316L containing a high concentration of chrome (Cr) and lower concentration of nickel (Ni) in order that a fraction of ferrite can be stabilized during solidification. There is, also, the use of welded metal combination containing 30% of ferrite associated to helium as protection gas. The weld joint obtained is austenito-ferritie, giving a structure with content in adequate ferrite of 15%, this leads to the expected mechanical characteristics which is the closest to the band of scatter of the base metal.