Jubica

Jubica

she/her

Doctoral researcher at Ghent University, specializing in hydrogen’s impact on pipeline steels for safe hydrogen infrastructure.

Characterization of Secondary Carbides in Low-Alloyed Martensitic Model Alloy Tool Steels

Published in Swerim AB, KTH Royal Institute of Technology, 2020

Keywords: Martensitic steel; Secondary hardening; Precipitation; STEM; EDS; Prisma; Size distribution

Overview

This master’s thesis investigates the microstructural evolution of secondary carbides in low-alloyed martensitic model alloy tool steels. The study focuses on understanding how different alloying elements and heat treatments influence the final properties of tool steels, which is crucial for optimizing their performance in industrial applications.

Research Objectives

  • Analyze the effect of alloying elements on phase transformations
  • Characterize microstructural evolution during heat treatment
  • Correlate mechanical properties with microstructural features
  • Develop guidelines for optimizing tool steel compositions

Methodology

  • Design and preparation of model alloy compositions
  • Heat treatment under controlled conditions
  • Microstructural characterization using SEM, TEM, and XRD
  • Mechanical testing including hardness, tensile, and impact testing
  • Fractography analysis

Key Findings

  • Identification of optimal alloying element combinations
  • Characterization of carbide formation and distribution
  • Correlation between heat treatment parameters and mechanical properties
  • Development of processing-structure-property relationships

Conclusions

This research provides fundamental insights into the design of high-performance tool steels through controlled alloying and heat treatment. The findings contribute to the development of next-generation tool steels with enhanced mechanical properties and service life.

Acknowledgments

This research was conducted in collaboration between Swerim AB and KTH Royal Institute of Technology in Stockholm, Sweden. I am deeply grateful to Erik Claesson at Swerim AB for his expert guidance on martensitic steels and characterization techniques, and to Prof. Peter Hedström at KTH for his invaluable supervision. Special thanks to Hans Magnusson for ThermoCalc support, and to my family and friends for their unwavering support throughout this journey.