In this paper we discuss the microstructure of lath martensitic steels and the mechanisms by which it controls cleavage fracture. The specific experimental example is a 9Ni (9 wt% Ni) steel annealed to have a large prior austenite grain size, then examined and tested in the as-quenched condition to produce a relatively coarse lath martensite. The microstructure is shown to approximate the recen...

An ultra-fine-grained AISI 301LN austenitic stainless steel has been achieved by heavy cold rolling, to induce the formation of martensite, and subsequent annealing at 800 C, 900 C, and 1000 C, from 1 to 100 seconds. The microstructural evolution was analyzed using transmission electron microscopy and the yield strength determined by tension testing. Ultra-fine austenite grains, as small as ~0....

R. Bakić, Tutin High School, Serbia, M. O. Abukresh, A. Sedmak. Faculty of Mechanical Engineering, University of Belgrade, Serbia, I. Samardžić, Faculty of Mechanical Engineering, Slavonski Brod, University of Osijek, Croatia, R. Jovičić, Innovation centre of the Faculty of Mechnical Engineering, Belgrade, Serbia Complex microstructure of austenite-ferrite welded joint has been investigated, fo...

to investigate the effect of tempering treatment on mechanical properties and the microstructure ofdin 1.4021 martensitic stainless steel, austenite treatment was conducted for the samples at 1000ºc temperature for 60 min and then the samples were oil quenched. later, tempering treatments wereperformed for the samples at 500 ºc and 700 ºc temperatures for 2 and 5 h, respectively; then quenching...

A directional solidification technique was developed and applied to the problem of fractional crystallization of an iron meteorite parent body. Samples of Fe-Ni alloys close to meteorite compositions and containing S, P, and C were made. The solidified structures contain secondary phases such as sulphides within the proeutectic single crystal austenite (taenite). As a result of these experiment...

Electron beam welds between dissimilar stainless steels with different solidification modes were studied with a view to elucidating the role of nucleation, cooling rate and direction of dendrite growth on the tendency towards metastable phase solidification. The results are compared with the solidification behaviour of levitation melted samples. It is demonstrated that with careful design, stai...

Deformation mechanisms of as-deposited and post-annealed Ti50.2Ni49.6, Ti50.3Ni46.2Cu3.5 and Ti48.5Ni40.8Cu7.5 thin films were investigated using the in situ synchrotron X-ray diffraction technique. Results showed that initial crystalline phases determined the deformation mechanisms of all the films during tensile loading. For the films dominated by monoclinic martensites (B19'), tensile stress...

The electronic structure and magnetism of the Heusler alloy Mn2NiAl have been studied by firstprinciples calculations. It is found that the phase transformation from the cubic to the tetragonal structure lowers the total energy, indicating that the martensitic phase is more stable and that a phase transition from austenite to martensite may happen at a lower temperature. Thus, ferromagnetic sha...

Article history: Received 10.9.2012 Received in revised form 10.12.2012 Accepted 10.12.2012 27SiMn steels with different original structures were zero time holding quenched after pretreatments including general quenching and normalizing, respectively, then their tensile strength and hardness were determined and also microstructures were analyzed.. The experimental results show that thus quenche...

The effect of stress and strain on the transformation kinetics of pearlite is investigated by phase-field simulation. Strain is considered in terms of expansion/contraction during transformation and due to concentration gradients in austenite. It is demonstrated that due to the concentration dependence of the eigenstrain, an inhomogeneous stress distribution ahead of the transformation front en...