No abstract

No abstract

The aim of the study is to assess the constraint effect induced by variation of geometric parameters on fracture toughness of stainless steel 304L thin sheets. A combined experimental-computational method is used. Compact Tension (CT) tests are firstly done using a special device realized to avoid buckling problems. Finite element analysis is used including the GTN (Gurson-Tvergaard-Needleman) model based on micromechanical assumptions of ductile fracture to obtain crack propagation. The fracture toughness is evaluated using an incremental formulation of the J-Integral. The results obtained show a quantified dependency of the critical fracture toughness on the constraint effect.

In recent years, the development of high-strength steels such as multi-phase TRIP (transformation-induced plasticity)-aided steels have shown great promise due to their excellent combination of high strength and ductility. In this paper, the effect of strain-induced martensitic transformation on mechanical properties is studied. Uniaxiale tension tests at different strain rate (10, 15 and 20 mm / min) are conducted at 25° C in order to characterize the mechanical behavior of AISI 304L. The microstructure, particularly retained austenite, is analyzed using optical microscopy, Vickers hardness measurements. The results showed that all properties measured are increased from (Re=390.96MPa to Re=425.96MPa and Hv=300.94Hv to 343.51HV). Secondly, the influence of the annealing treatment on microstructure and mechanical properties of the joint formed by the spot welding are characterized using tensile test, metallographic analysis and Vickers hardness measurements.