Evolution of the residual stress state in a duplex stainless steel during loading

Journal Article · Fri Jul 09 04:00:00 EDT 1999 · Acta Materialia

DOI:https://doi.org/10.1016/S1359-6454(99)00149-4· OSTI ID:6448858

Johansson, J; Oden, M; Zheng, X H ^[1]

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1. Linkoeping Univ. (Sweden). Div. of Engineering Materials

The evolution of micro- and macrostresses in a duplex stainless steel during loading has been investigated in situ by X-ray diffraction. A 1.5 mm cold-rolled sheet of alloy SAF 2304 solution treated at 1,050 C was studied. Owing to differences in the coefficient of thermal expansion between the two phases, compressive residual microstresses were found in the ferritic phase and balancing tensile microstresses in the austenitic phase. The initial microstresses were almost two times higher in the transverse direction compared to the rolling direction. During loading the microstresses increase in the macroscopic elastic regime but start to decrease slightly with increasing load in the macroscopic plastic regime. For instance, the microstresses along the rolling direction in the austenite increase from 60 MPa, at zero applied load, to 110 MPa, at an applied load of 530 MPa. At the applied load of 620 MPa a decrease of the microstress to 90 MPa was observed. During unloading from the plastic regime the microstresses increase by approximately 35 MPa in the direction of applied load but remain constant in the other directions. The initial stress state influences the stress evolution and even after 2.5% plastic strain the main contribution to the microstresses originates from the initial thermal stresses. Finite element simulations show stress variations within one phase and a strong influence of both the elastic and plastic anisotropy of the individual phases on the simulated stress state.

• OSTI ID: 6448858
• Journal Information: Acta Materialia, Journal Name: Acta Materialia Vol. 47:9; ISSN 1359-6454; ISSN ACMAFD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360103* -- Metals & Alloys-- Mechanical Properties
ALLOYS
CALCULATION METHODS
COHERENT SCATTERING
COMPUTERIZED SIMULATION
DIFFRACTION
DYNAMIC LOADS
FINITE ELEMENT METHOD
HIGH ALLOY STEELS
IRON ALLOYS
IRON BASE ALLOYS
NUMERICAL SOLUTION
RESIDUAL STRESSES
SCATTERING
SIMULATION
STAINLESS STEELS
STEELS
STRAINS
STRESSES
X-RAY DIFFRACTION