Many traditional approaches for strengthening steels typically come at the expense of useful ductility, a dilemma known as strength-ductility trade-off. New metallurgical processing might offer the possibility of overcoming this. Here we report that austenitic 316L stainless steels additively manufactured via a laser powder-bed-fusion technique exhibit a combination of yield strength and tensile ductility that surpasses that of conventional 316L steels. High strength is attributed to solidification-enabled cellular structures, low-angle grain boundaries, and dislocations formed during manufacturing, while high uniform elongation correlates to a steady and progressive work-hardening mechanism regulated by a hierarchically heterogeneous microstructure, with length scales spanning nearly six orders of magnitude. In addition, solute segregation along cellular walls and low-angle grain boundaries can enhance dislocation pinning and promote twinning. This work demonstrates the potential of additive manufacturing to create alloys with unique microstructures and high performance for structural applications.

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Additively manufactured (AM) metallic materials commonly possess substantial microscale internal stresses that manifest as intergranular and intragranular residual stresses. However, the impact of these residual stresses on the mechanical behaviour of AM materials remains unexplored. Here we combine in situ synchrotron X-ray diffraction experiments and computational modelling to quantify the lattice strains in different families of grains with specific orientations and associated intergranular residual stresses in an AM 316L stainless steel under uniaxial tension. We measure pronounced tension–compression asymmetries in yield strength and work hardening for as-printed stainless steel, and show they are associated with back stresses originating from heterogeneous dislocation distributions and resultant intragranular residual stresses. We further report that heat treatment relieves microscale residual stresses, thereby reducing the tension–compression asymmetries and altering work-hardening behaviour. This work establishes the mechanistic connections between the microscale residual stresses and mechanical behaviour of AM stainless steel.

The supercritical water oxidation process (SCWO) is of great interest today in recycling toxic and/or complexed chemical wastes with very good eciency. When reaching the critical conditions (374°C, 22.1 MPa), polarity collapses and water becomes a very good solvent for organic compounds. However, these interesting properties for organics turn to be problematic regarding dissolved inorganics. Commonly present in the aqueous waste, those inorganics precipitate easily when approaching the critical domain, leading to plugs in the process. In order to better understand the precipitation of salts in supercritical water, their solubility behaviour is of main interest. However, lots of relevant data are still missing in the literature. The aim of this review is to summarise most of the existing data regarding salt solubility in sub-and supercritical water as well as the dierent set up and methods developed over the past 50 years, including predictive theoretical modeling.

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