The stress-induced transformation behavior of retained austenite is considered in this work. With the development of transformationinduced plasticity (TRIP) steels this deformation mode is of growing importance. Twinned martensite structures were calculated using the crystallographic theory of martensite. An available work criterion was used to predict the transformation potentials for 16 diffe...

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,...

the effect of ferrite grain size on the fatigue and tensile properties of dual phase steels with a 0.25 volumefraction of martensite (vm) under different heat treatments was investigated. the heat treatments werehomogenized at 1200 oc along with several subsequent normalizations at 910 oc, resulting in differentmicrostructures and mechanical properties. after heat treatment, the obtained steels...

An array of aromatic aldehydes with electron withdrawing groupunderwent crossed-Aldol condensation with cycloalkanone in the presence of catalytic amounts of DBSA under aqueous media to afford the corresponding α, ά-bis(substituted-benzylidene) cycloalkanones in good yields. The electronic effects on aromatic aldehydes could be observed. The present method is operationally simple and use of wat...

In this research, variant selection of martensite transformed from ultrafine-grained (UFG) austenite fabricated by accumulative roll bonding (ARB) process and subsequent annealing was investigated with respect tomorphology of parentaustenitic phase. The results show that the original shape of austenite grain is very effective factor in determiningthe preferred variants of martensite transformed...

Examination of a time–temperature–transformation (TTT) diagram for an eutectoid carbon steel (Fig. 1), bearing in mind the fact that the pearlite reaction is essentially a high temperature one occurring between 550C and 720C and that the formation of the martensite is a low-temperature reaction, reveals that there is a wide range of temperature ∼250–550C within which neither of these phases for...

We study the symmetrised rank-one convex hull of monoclinic-I martensite (a twelve-variant material) in the context of geometrically-linear elasticity. We construct sets of T3s, which are (non-trivial) symmetrised rank-one convex hulls of three-tuples of pairwise incompatible strains. In addition, we construct a fivedimensional continuum of T3s and show that its intersection with the boundary o...

The most efficient way to tune microstructures and mechanical properties of metallic alloys lies in designing and using athermal phase transformations. Examples are shape memory alloys and high strength steels, which together stand for 1,500 million tons annual production. In these materials, martensite formation and mechanical twinning are tuned via composition adjustment for realizing complex...

The stabilization of retained austenite was studied via a two-step cooling procedure. Alloys with M , temperatures below 0 OC were used. It was found that the martensitic transformation starting temperature, M,, was lowered to M,' during the second step of cooling. With increasing the amount of previously formed martensite, the difference in the transformation starting temperatures, AM, (= M,M,...

Ti-Nb-based Gum Metals exhibit extraordinary superelasticity with ultralow elastic modulus, superior strength and ductility, and a peculiar dislocation-free deformation behavior, most of which challenge existing theories of crystal strength. Additionally, this kind of alloys actually displays even more anomalous mechanical properties, such as the non-linear superelastic behavior, accompanied by...