High-resolution X-ray diffraction investigation on the evolution of the substructure of individual austenite grains in TRIP steels during tensile deformation

The martensitic transformation behaviour of the metastable austenite phase in low-alloyed transformation-induced plasticity (TRIP) steels has been studied in situ using high-energy X-ray diffraction during deformation. The austenite stability during tensile deformation has been evaluated at different length scales. A powder diffraction analysis...

Residual stress measurements and model validation of single and double pulse resistance spot welded advanced high strength steel

Advanced high strength steels (AHSS) are increasingly used in automotive industry; thousands of resistance spot welds are applied to car body-in-white. High alloying levels of AHSS result in lower weldability. Residual stresses play an essential role on the formation of defects and the mechanical performance of the weld. An electrical-thermal...

Interplay between metastable phases controls strength and ductility in steels

By means of high-energy synchrotron X-ray diffraction, the interplay between martensite and retained austenite phases in steel during the application of stress has been analyzed. Martensite properties were varied through controlled reheating heat treatments in a low carbon Quenched and Partitioned (Q&P) steel consisting of retained...

Microstructural stability of secondary phases in an ODS ferritic steel after thermal aging at 873 K

An oxide dispersion strengthened (ODS) steel with nominal composition Fe–14Cr–2W–0.4Ti–0.3Y₂O₃ (wt%) has been manufactured by mechanical alloying of pre-alloyed powders with nanosized Y₂O₃, compacted by hot isostatic pressing and hot cross rolled. In order to evaluate the long-term thermal...