Precipitation Behaviour of a Complex Steel

Abstract

Nanometer‐sized precipitates in tool steels are the most important microstructural constituents determining the mechanical and thermophysical properties. For the improvement of existing steel grades and the development of new tool steels a fundamental knowledge of the precipitation reactions during heat treatments and at application temperature is of vital interest. Thus, a comprehensive characterization of the various precipitates is required. This paper reviews the studies performed on a complex tool steel which hardens by secondary hardening carbides and intermetallic phases using advanced methods for characterizing nm‐sized precipitates, such as transmission electron microscopy, atom probe field ion microscopy and small‐angle neutron scattering. Additionally, computer simulations of the precipitation kinetics were performed using a novel model for nucleation, growth and coarsening of spherical precipitates in multi‐component, multi‐phase systems. It is demonstrated how experiments and simulations fit together and how thoroughly obtained experimental data help to validate and improve the theoretical models.

(Nb,Ti)(C,N)‐Precipitates in High‐Strength Low‐Alloyed Steels—Modeling, Characterization and Validation

“…Most publications only present mean values of the measured data or grade the particles according to their dominant anions. [12,13,33,34] Most of the time, precipitation compositions are assumed to be stoichiometric [35] or at equilibrium composition, either calculated using a thermodynamic approach [16,36,37] or based on solubility products. [21,27] Only studies by Dijk et al [38] and Craven et al [8] showed the spread in composition for a handful of particles.…”

Practical applications of small-angle neutron scattering

“…133 Additionally, the importance of evidence from microscopy techniques cannot be ignored as this provides critical information that can be fed into the SANS data modelling to increase accuracy. 78,79,[81][82][83][84][100][101][102]112,114,115,120,125 In the condensed phase, the combination of multiple techniques can be used to build up detailed pictures, such as those established for P3HT gels and films. [84][85][86][92][93][94][95] The ability to generate such detail is clearly of benefit to the identification of structureproperty relationships and SANS has a crucial role to play, particularly in determining the statistically significant structural parameters.…”

“…It is hoped that this review has demonstrated the wealth of ways in which SANS can be exploited for the characterisation of materials systems. In particular, the use of contrast matching 5,19,42,49,99,119 or magnetic scattering 125,127,129,132 has been shown to be a valuable way to optimise experiments by highlighting structures of interest. Throughout the described examples, high importance is placed on the application of SANS alongside other scattering techniques.…”

Computational Analysis of Precipitation during Continuous Casting of Microalloyed Steel

“…The results of this simulation are then used in a second step to predict the precipitation kinetics of carbides and nitrides in the segregated and non‐segregated regions of the primary solidification microstructure. Successful application of the corresponding precipitation kinetics model have been reported previously 15, 16.…”