The structure and mechanical properties of new dispersion-hardened Mn-(Cr)-Si-V-C steels with a shape memory effect (SME), which undergo strengthening due to the precipitation VC carbides in steel matrix, were analyzed. stabilizing destabilizing carbide aging at different temperatures allows one control thus adjust desired strength characteristics (σ0,2 = 250–880 MPa) amount reversible deformat...

Calculations verify that carbon diffusion may occur during the lath martensite fomtion. Accordingly,the diffusion of int2rstitial ator ions must be taka into account nhfn martmitic transformtion is defined as a diffusionless transformation. In derivation of the kinetics equation of the ath& martensitic transfomtion,rzgardng the c a r h diffusion, i .e.the enrichment of the austenite during the ...

Abstract In situ tensile tests employing digital image correlation were conducted to study the martensitic transformation of oligocrystalline Fe–Mn–Al–Ni shape memory alloys in depth. The influence different grain orientations, i.e., near-〈001〉 and near-〈101〉, as well boundary misorientations are focus present work. results reveal that reversibility martensite strongly depends on type evolving,...

This paper represents an attempt to understand, from basic principles, the origins of hysteresis during variant rearrangement. As a framework for this study, we focus on the biaxial loading experiments conducted in 171 on single crystals of 7; martensite, oriented so that two compound twinned variants of martensite have least energy. Our analysis supports the idea that hysteresis (at least in t...

The martensite steels produced by quenching and tempering has been used for machine structural use. Martensite in ferrite-martensite dual-phase steels (hereinafter, DP steels) also has important roll in strengthening of the automobile steel sheets. Therefore the importance of analyzing the microstructure and their mechanical properties of the martensite has been increased year by year. Many res...

Deformation and work hardening behavior of Fe-17Mn-0.02C steel containing ε-martensite within the austenite matrix have been investigated by means of in situ microstructural observations and x-ray diffraction analysis. During deformation, the steel shows the deformation-induced transformation of austenite → ε-martensite → α'-martensite as well as the direct transformation of austenite → α'-mart...

Deformation behavior and microstructure evolution of NiTiCu shape memory alloy (SMA), which possesses martensite phase at room temperature, were investigated based on a uniaxial compression test at the temperatures of 700~1000 ◦C and at the strain rates of 0.0005~0.5 s−1. The constitutive equation of NiTiCu SMA was established in order to describe the flow characteristic of NiTiCu SMA, which is...

The austenite-to-martensite transformation in a partially hardened stainless steel containing 17wt %Cr, 7wt %Ni and 1wt % Al was investigated with Vibrating Sample Magnetometry and Electron Back-Scatter Diffraction. Magnetometry demonstrated that measurable martensite formation can be suppressed on fast cooling to 77K as well as on subsequent fast heating to 373 K. Surprisingly, martensite form...

The austenite-to-martensite transformation in a partially hardened stainless steel containing 17wt %Cr, 7wt %Ni and 1wt % Al was investigated with Vibrating Sample Magnetometry and Electron Back-Scatter Diffraction. Magnetometry demonstrated that measurable martensite formation can be suppressed on fast cooling to 77K as well as on subsequent fast heating to 373 K. Surprisingly, martensite form...