The impact of microstructure evolution on mechanical properties in superduplex stainless steel UNS S32750 (EN 1.4410) was investigated. To this end, different thermomechanical treatments were carried out order to obtain clearly distinct duplex microstructures. Optical microscopy and scanning electron microscopy, together with texture measurements, used characterize the morphology preferred orie...

The shape memory effect exhibited by Fe-Mn-Si based alloys is due to the y(f.c.c.)-e(h.c.p.) martensitic transformation. The martensitic transformation induced by traction at room temperature in a Fe16Mn-9Cr-5Si-4Ni (%mass) is here studied by optical microscopy, scanning electron microscopy, transmission electron microscopy and scanning tunnelling microscopy. The martensitic microstructure and ...

It is increasingly important in the context of high–manganese steels of the kind that lead to twinning–induced plasticity to be able to estimate the temperature at which ε–martensite forms when austenite is cooled. We find that the thermodynamic method used in similar calculations for α martensite cannot in many cases be implemented because of apparently imprecise thermodynamic data, a conclusi...

The formation of stress-induced α′′ martensite in a metastable β Ti-Mo-based alloy has been studied using X-ray diffraction and transmission electron microscopy. The martensite nucleates heterogeneously at pre-existing sub-grain boundaries by dissociation of the boundary dislocations which bow out on inclined planes. The growth of martensite laths from the resultant stacking faults occurs by th...

Abstract The deployment of Press Hardened Steels (PHSs) in the Body-In-White structures that took place during two last decades is at origin a breakthrough weight saving on vehicles while guaranteeing safety requirements automotive industry. production parts with complex shapes and high strength between 1500-2000MPa was made possible by taking advantage hot rheology austenite combined fast cool...

This conference paper briefly discusses different techniques for measuring the evolution of the martensite content in cold-rolled stainless steel 301LN sheets under mechanical loading. Three methods are employed to measure the martensite content: (1) micrography, (2) bulk magnetic induction, and (3) local magnetic permeability measurements. The first two methods require the extraction of sample...

Modulated phases occur in numerous functional materials like giant ferroelectrics and magnetic shape-memory alloys. To understand the origin of these phases, we employ and generalize the concept of adaptive martensite. As a starting point, we investigate the coexistence of austenite, adaptive 14M phase, and tetragonal martensite in Ni-Mn-Ga magnetic shape-memory alloy epitaxial films. We show t...

In hot rolled products, which are the subject of other presentations here, vanadium has been used for many years in high strength products, often in combination with other microalloying additions such as niobium or titanium. Vanadium can provide important contributions via both precipitation strengthening and ferrite grain refinement (due to austenite conditioning during thermomechanical proces...