Residual Thermal Phase Stresses in α-γ Fe-Cr-Ni Alloys Measured by a Neutron Diffraction Time-of-Flight Method

Abstract

Residual thermal phase elastic strains in rod specimens and powders with particle size from 150 to 250 µm of α-γ Fe-Cr-Ni alloys quenched from 1273 to 273 K, were measured by means of a high-resolution neutron powder diffractometer using a time-of-flight (TOF) method. Diffraction patterns were analyzed by the Rietveld method and the single-peak method. Residual thermal phase strains obtained in the rod specimens or the powders from the both methods are positive, i.e., tensile, for austenite (γ ) phase and negative for ferrite (α) phase, being consistent with the prediction from the difference in thermal expansion coefficients of the constituent phases. The Rietveld analysis combined with the TOF method is considered to give the most reliable results of the average thermal phase strain. The results by the single-peak analysis suggest that thermal phase strain shows [hkl] dependence; the absolute value of thermal phase strain is decreased with increasing of the Young modulus along the [hkl] direction.

Unravelling thermal history during additive manufacturing of martensitic stainless steel

“…The compressive stresses acting on the martensite resulted preferentially from transformation strain and additionally from thermal misfit strain induced by the difference in the thermal expansion rate between the two phase constituents [ 20 , 32 , [34] , [35] , [36] , [37] ]. A slight tensile thermal strain acting on the retained austenite was due to the development of tensile stresses that balanced the compressive stresses acting on the martensite [ [19] , [20] , [21] , 33 , 34 , 38 ].…”

Lattice strain estimation for CoAl2O4 nano particles using Williamson-Hall analysis

“…Since, the E hkl of cubic CoAl 2 O 4 nanoparticles is already known then the strain can be determined. Young's modulus E hkl for samples with a cubic crystal phase is related to their elastic compliances S ij (for CoAl 2 O 4 S 11 = 6.07 , S 12 = -3.83 and S 44 = 7.22 TPa -1 ) as [33]:…”

Influence of Metal (Al, Mg, Sm, and Cu) Dopants on Structural, Optical, Magnetic, and Antimicrobial Properties of ZnO Nanopowders Synthesized by Coprecipitation Method

“…The bond length of Zn–O is estimated using the formula [ 40 ] …”