Interdendritic microsegregation development of high-strength low-alloy steels during continuous casting process

Abstract

A 1-D model based on DICTRA software was used to simulate Mn microsegregation in high-strength low-alloy steels during continuous casting. The experimentally determined (using a cumulative profiling method) segregation results were in good agreement with the modelling results. Steels undergoing solidification via a peritectic reaction had a larger segregation range than non-peritectic steels ascribed to trapping of the alloying atoms in liquid by austenite acting as a diffusion barrier. Subsequent, post-solidification cooling through the single phase austenite field decreased the microsegregation level, although the last γ→ α phase transformation did affect the segregation profile in the solute-depleted dendrite centre. Simulation indicates that segregation levels could be reduced by decreasing either secondary dendrite arm spacing or adopting faster cooling rates through solidification.

A Comparative Study of Microstructural Characteristics and Mechanical Properties of High-Strength Low-Alloy Steel Fabricated by Wire-Fed Laser Versus Wire Arc Additive Manufacturing

“…High-strength low-alloy (HSLA) steels are widely utilized in structural applications owing to their combination of strength, ductility, toughness, weldability, and cost-effectiveness [14]. Achieving the desired balance of strength and toughness involves a careful alloy composition design and the use of thermomechanical control processing (TMCP) [15,16]. Wire-based additive manufacturing offers a swift and economical means of producing intricate parts from HSLA steels, particularly in marine and offshore engineering applications such as a marine drilling platform rack.…”

The Effect of Micro-Segregation on the Quantification of Microstructural Parameters in Grade 91 Steel

“…Reliable quantitative microstructural data are also required to feed into creep damage models for these materials. [27] It is clear that micro-segregation can have significant effects in other steel types such as those detailed for high-strength low-alloy (HSLA) steels [28][29][30] and in automotive grades, [31] where the effects of segregation on precipitation and grain structure affecting properties and property scatter have been identified. In the case of HSLA steels, a study by Wang et al regarding the segregation of Nb showed a subsequent formation of an increased amount of Nb-rich precipitates in the interdendritic regions resulting in a banded microstructure with a bimodal grain size distribution.…”