Development of Ni-free Mn-stabilised maraging steels using Fe2SiTi precipitates

Research output: Contribution to journalArticlepeer-review

Authors

  • Peng Gong
  • Khandaker M Rahman
  • W Mark Rainforth
  • David Dye
  • Enrique I Galindo-Nava

Colleges, School and Institutes

External organisations

  • University of Sheffield
  • Imperial College London
  • University of Cambridge

Abstract

Computational alloy design has been used to develop a new maraging steel system with low cost, using Mn for austenite reversion and Heusler Fe2SiTi nm-scale precipitates to strengthen the martensite, avoiding high cost alloying elements such as Ni and Co. A pronounced ageing response was obtained, of over 100 HV, associated with the formation of 2-30nm Fe2SiTi precipitates alongside the development of ⇠10% Mn rich austenite, at the martensite boundaries with the Kurdjumov-Sachs orientation relationship. The precipitates took on different orientation relationships, depending on the size scale and ageing time, with fine ⇠ 5nm precipitates possessing an <100>L21//<100>α orientation relationship, compared to larger ⇠ 20 nm precipitates with <110>L21//<100>α. Computational alloy design has been used for the development and demonstration of an alloy design concept having multiple constraints. Whilst in this case computational design lacked the fidelity to completely replace experimental optimisation, it identifies the importance of embedding Thermodynamic and kinetic modelling within each experimental iteration, and vice versa, training the model between experimental iterations. In this approach, the model would guide targeted experiments, the experimental results would then be taken into future modelling to greatly accelerate the rate of alloy development.

Details

Original languageEnglish
Pages (from-to)260-270
Number of pages11
JournalActa Materialia
Volume174
Early online date21 May 2019
Publication statusPublished - 1 Aug 2019

Keywords

  • Steels, Precipitation, Microstructure, Mechanical Properties, Transmission Electron Microscopy