the formation of nano/ultrafine grained ferrite in low carbon steels containing different amounts of niobiumwas investigated using thermomechanical treatment which consisted of annealing of 85% cold rolled martensite with different parameters. the specimens were characterized by optical and scanning electron microscopy and vickers hardness test. a lamellar dislocation cell structure was formed ...

A generalized phase transformation kinetics model is used to understand the martensite to austenite transformation in a cold-rolled and annealed metastable AISI 301LN ultrafine-grained austenitic stainless steel. The model shows that the presence of interstitial nitrogen and heavy cold-rolling is important to promote fast transformation kinetics, through rapid nitrogen-diffusion and austenite n...

Nano/submicron austenitic stainless steels have attracted increasing attention over the past few years due to fine structural control for tailoring engineering properties. At the nano/submicron grain scales, grain boundary strengthening can be significant, while ductility remains attractive. To achieve a nano/ submicron grain size, metastable austenitic stainless steels are heavily cold-worked,...

Formation of nano/ultrafine grain structure in AISI 304L austenitic stainless steel through the martensite reversion treatment was studied. The solution annealed specimens were cold rolled up to 95 % thickness reduction at -15°C. The cold-rolled specimens were subjected to reversion annealing treatment at the temperature range of 700-1000 °C for 10–150 min. Microstructural evolutions were analy...

in this study, the effects of nitrogen addition on the production of ultrafine/nano grained aisi 201l stainlesssteel by advanced thermo-mechanical process were investigated. cast samples were first homogenized at 1200 °c for 4 h, hot-rolled at 1100 °c and finally, solution-annealed at 1150 °c for 2.5 h. unidirectional and cross multipass cold rolling at 25 °c was carried out to 90% reduction in...

In this study, the effects of nitrogen addition on the production of ultrafine/nano grained AISI 201L stainless steel by advanced thermo-mechanical process were investigated. Cast samples were first homogenized at 1200 °C for 4 h, hot-rolled at 1100 °C and finally, solution-annealed at 1150 °C for 2.5 h. Unidirectional and cross multipass cold rolling at 25 °C was carried out to 90% reduction i...

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...

We present results from a systematic study linking material microstructure to monotonic and fatigue properties of NiTi shape memory alloys. We consider Ni-rich materials that are either (1) hot rolled or (2) hot rolled and cold drawn. In addition to the two material processing routes, heat treatments are used to systematically alter material microstructure giving rise to a broad range of therma...

The texture of cold-rolled and heat-treated TiNi sheet has been measured and designated as {110}(1i0)p. This material has been used in thermal fatigue tests during and after which the anisotropy and development of several thermomechanical properties, such as transformation temperatures and strains, have been measured. Furthermore, the resulting changes of texture after thermal fatigue are prese...