SAXS and TEM Quantitative Analysis of Plate-like Precipitates in Ti-added Low-carbon Steel

Characterization of Deformation by Cold Rolling in Ferritic Steel Containing Cu Particles Using Neutron Transmission Analysis

“…18) The function I(q) denotes the q-dependent scattering intensity, which is measured by conventional SANS experiments and reflects the shape, size, number density, and scattering contrast of nanoscale inhomogeneities. [6][7][8][9][10][11] Here, q is the magnitude of the scattering vector and written as q = 4πsin(θ)/λ. In the Cu steels, transmission electron microscopy (TEM) has confirmed that the Cu particles are only slightly elongated before the cold rolling and then markedly transformed to elongated spheroids.…”

“…[1][2][3][4][5] In contrast, small-angle neutron scattering (SANS) can provide nanostructural information about precipitates and inclusions. [6][7][8][9][10][11] The combination of neutron diffraction and SANS is effective to understand the total behaviors of the microstructures in steels, for example, simultaneous progress of the texture evolution and precipitation. In addition, neutron transmission measurements are also useful for the microstructural characterization.…”

Quantitative SAXS Analysis of Precipitate Characteristics Limiting Hot Ductility in HSLA Steels Containing V, Nb & NbTi

“…X-ray beams can measure areas more than 100 × larger than standard transmission electron microscopy (TEM) analysis and SAXS techniques have shown a comparable ability to accurately measure spherical and plate-like particles. 5,6) In the current study, analysis of continuously cast HSLA steels using SAXS provided an advantage in characterization of precipitate structures and relatively rapid identification of the impact they may have on the high-temperature mechanical properties of steel. Steels with Nb, Ti, V, and N microalloying additions were evaluated to determine how precipitate size, spacing, and volume fraction influence hot ductility behavior of several HSLA steel grades.…”

“…A spherical shape factor was used for this analysis because the specific particle shape for each steel grade was unknown and because shape factor is not expected to significantly affect the SAXS analysis results. 5) P r r q I q qr qr dq ( ) ( ) sin( ) = ∫ P(r) is the pair distribution function, I(q) is the intensity function, q is the scattering vector, and r is the real space distance. Median particle spacing values or the particle spacing with the highest probability, as determined from the P(r) histogram will be defined as interparticle spacing values for this analysis, representing the relative spacing between particles in the measured material.…”

“…Figure 3(a) demonstrates a power-law relation which in this case likely indicates that there is wide variability in particle size and limited systematic ordering. 5) The Guinier region used to estimate particle size is identified in Fig. 3(b).…”