Effect of processing parameters on texture and variant selection of as-built 300 maraging steel processed by laser powder bed fusion.

Among the materials that might be manufactured with laser powder bed fusion (LPBF), one can highlight maraging steels, with excellent weldability, strength and fracture toughness. However, the effects of the processing parameters and the mechanisms governing the as-built texture are not clear yet. A recent publication showed a low texture index in the prior austenite, in contrast to other alloys subjected to LPBF with the same strategy.

Positron Annihilation Spectroscopy Study of Carbon-Vacancy Interaction in Low-Temperature Bainite.

Nano-scale investigations of bainitic structures formed at temperatures below 350 °C have shown that the bainitic ferrite lattice is super-saturated in carbon. A high density of intrinsic defects would be playing a part in the carbon-supersaturation levels detected. In this work, the role of C-vacancy complexes on carbon-supersaturation in low temperature bainite is investigated by means of Positron Annihilation Spectroscopy.

The Non-Steady State Growth of Pearlite outside the Hultgren Extrapolation.

The goal of this paper is to analyse the effect of adding Al on the non-steady pearlite growth occurring in a Fe-C-Mn system. The results are discussed in terms of the partitioning of elements across the austenite/ferrite and austenite/cementite interfaces, and the modification of the pearlite driving force related to the change in carbon activity in austenite.

Comparison of Ductile-to-Brittle Transition Behavior in Two Similar Ferritic Oxide Dispersion Strengthened Alloys.

The ductile-to-brittle transition (DBT) behavior of two similar Fe-Cr-Al oxide dispersion strengthened (ODS) stainless steels was analyzed following the Cottrell-Petch model. Both alloys were manufactured by mechanical alloying (MA) but by different forming routes. One was manufactured as hot rolled tube, and the other in the form of hot extruded bar.

Influence of Texture on Impact Toughness of Ferritic Fe-20Cr-5Al Oxide Dispersion Strengthened Steel.

Fe-based oxide dispersion strengthened (ODS) steels are oriented to applications where high operating temperatures and good corrosion resistance is paramount. However, their use is compromised by their fracture toughness, which is lower than other competing ferritic-martenstic steels. In addition, the route required in manufacturing these alloys generates texture in the material, which induces a strong anisotropy in properties.