δ/γ Interface bondary sliding as a mechanism for strain accommodation during hot deformation in a duplex stainless steel

Abstract

A. PIÑ OL-JUEZ, A. IZA-MENDIA, and I. GUTIÉ RREZ In the present work, the mechanical properties and the microstructural evolution of a duplex stainless steel in the as-cast and wrought conditions during deformation under hot-working conditions have been studied. Hot torsion tests, at strain rates of ϭ 1 s Ϫ1 , have been carried out using prepolished samples on which surface parallel scratches have been practiced. The observation of the surface of the samples shows a large displacement of the scratches produced by two different mechanisms, sliding on the ␦/␥ interface, and shearing of the ferrite. The displacements in the as-cast condition have been found to concentrate in a reduced set of ferrite/austenite interfaces leading to the formation of cracks along them. In the wrought material, the distribution of the sliding is more homogeneous over all the ferrite/austenite interfaces, and no damage has been produced. These behavioral differences between both materials have been related in the present work, to the characteristics of the corresponding microstructures, to the spatial phase distribution, and to the nature of the ferrite/austenite interface, among others.

High Temperature Deformation Behavior of Peritectic Carbon Steel during Solidification.

“…35) Figure 11 shows the change of tensile strength and elongation with fraction solid when the strain is generated for the Fe-0.14mass%C steel during solidification. The range of fraction solid was calculated by the solute redistribution model.…”

Correlation of Strain Accommodation Factor with the State of Microstructural Components in a Multiphase Steel

“…22) In addition to the different dynamic microstructural evolution of the two phases, the strength difference between the phases at hot working temperatures would affect the load transfer between both constituents in duplex/multiphase steel. 23,24) Consequently, the softer phase would be much easily plastically deformed than the harder phase, and is likely to accommodate most of the strain applied to the steel.…”

Conditions for the Efficient Crushing of the As-Cast Microstructure of 30Cr10Ni Duplex Stainless Steel

“…Therefore, the volume fractions of both phases have a large influence on the hot workability of DSSs. [5][6][7][8][9][10][11][12][13][14] The complexity during hot deformation also contributes to the different softening mechanisms of the ferrite and the austenite. Namely, during hot deformation, the ferrite phase, which is softer, exhibits dynamic recovery (DRV) or extended DRV, as was discussed in detail by the authors, [15,16] but some authors also report the occurrence of dynamic recrystallization (DRX) in the ferrite.…”

“…[24] Despite the great importance of the hot deformation of DSS, relevant publications that deal with their hot workability are lacking, especially for the as-cast state, as only a few publications can be found in the literature. [13,[25][26][27] Therefore, in this article, the hot workability of the 30Cr10Ni ferrous alloy, which belongs to the group of DSSs and normally is used as a welding material, has been considered. Its production, because of the higher content of Cr, Ni, and C in comparison with other commonly used DSSs, is characterized by the occurrence of cracks during hot deformation, which can originate from the hot deformation during its initial stage (i.e., the deformation of the as-cast state).…”