Post-processing tool for in-situ diffraction studies of phase transformations in metallic materials

Purpose and goal

Time-resolved diffraction experiments offer a unique opportunity to study phase transformations related to both production processes and the use of engineering materials. Post-processing and understanding a large set of data set after such experiments, however, is usually time-consuming and requires a level of manual adjustment of parameters and crystallographic knowledge which can be a drawback for industrial users. The aim of this project was to develop a simple fast post-processing tool to visualize and analyze time-resolved diffraction data from metallic materials.

Expected results and effects

Phase transformation of metallic materials during industrial processes is of a great importance for both material users and producers. The project has used the collaboration between a material producer (Outokumpu), an end-user (Alfa Laval) and a metal research institute (Swerim) to develop a user-friendly program to handles large sets of diffraction data. The results of this project will pave the way and make the use of in-situ experiments a simple routine for developing new alloys or new heat treatment processes and/or studying the behavior of materials under different conditions.

Planned approach and implementation

We have developed a toolbox to identify present phases within the structure, give a quantitative fraction of each phase, calculate lattice parameters, and provide information about the strain/stress within the lattice. The program can model thousands of diffraction patterns in only a few minutes and the use of it does not require crystallographic knowledge. We have used the program to analyze time-resolved diffraction data collected during heating and cooling cycles for duplex stainless steels, and also to calculate residual stress within steel materials.