On the origin of the tensile flow stress in the stainless steel AISI 316L at 300 K: back stress and effective stress
1999; Elsevier BV; Volume: 47; Issue: 13 Linguagem: Inglês
10.1016/s1359-6454(99)00222-0
ISSN1873-2453
Autores Tópico(s)Hydrogen embrittlement and corrosion behaviors in metals
ResumoThe tensile behaviour of a polycrystal austenitic stainless steel at 0.2Tm is discussed in terms of back and effective stresses with the help of qualitative and quantitative TEM observations. Particular attention is given to the transition between stages I and II which occurs at a plastic strain equal to 1.5%. The effective stress evolution can be interpreted as a competition process between the increase of mobile dislocation density and dislocation interactions and an annihilation process. The main purpose of this work is to provide a basis for separating the two different contributions of the back stress, namely the intragranular back stress Xintra arising from the heterogeneous dislocation distribution inside the grains and the intergranular back stress component Xinter resulting from plastic strain incompatibilities between grains. Moreover, it is shown that the latter contribution is dominant at small strains (stage I), whereas the former one is more important subsequently (stages II and III), when cross-slip and multiple slip occur.
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