Residual stress analysis for development of hydrogen embrittlement resistant high strength steels
|Coordinator||SSAB EMEA AB - SSAB Special Steel|
|Funding from Vinnova||SEK 497 000|
|Project duration||November 2018 - November 2019|
|Venture||Research infrastructure - utilisation and collaboration|
|Call||Industriella pilotprojekt för neutron- och fotonexperiment vid storskalig forskningsinfrastruktur 2018|
Purpose and goal
The objective here is to show the possibilities for residual stress analysis with neutron diffraction for development of high strength wear steels. The risk for Hydrogen embrittlement rises with higher strength due to increased residual stresses and these can be influenced by the processing conditions. Stresses are difficult to measure with conventional x-rays, since only the surface can be analyzed. Neutrons, used in this project, have a much larger penetration depth. The aim is to measure stresses through the plate thickness after different steps of the manufacturing process.
Expected results and effects
The expectation from the participants is a deeper understanding for the potential of residual stress measurements with the aid of neutron diffraction with the purpose to develop more hydrogen embrittlement resistant steels. The results from the suggested analysis will help the steel producer to minimize the detrimental residual stresses caused by the manufacturing process and it is highly likely that neutron diffraction will be a valuable tool to evaluate the effect of changes in the process on residual stresses in the future. The results will be published in a scientific journal.
Planned approach and implementation
The measurements will be performed at ENGIN-X, ISIS (UK), and consist of analysis of short and long range stresses through the thickness of the plate after different processing steps, i.e. quenching, tempering and levelling. These are the manufacturing steps that are expected to introduce, or affect, the residual stresses the most in as delivered condition. The aim is to obtain as high spatial resolution of the measurements as possible. The project participants consist of the steel producer SSAB EMEA AB, Malmö University and the research institute Swerim AB.