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Full-Text Articles in Engineering
Precipitation Behavior Of Magnetite In Oxide Scale During Cooling Of Microalloyed Low Carbon Steel, Xianglong Yu, Zhengyi Jiang, Daijun Yang, Dongbin Wei, Quan Yang
Precipitation Behavior Of Magnetite In Oxide Scale During Cooling Of Microalloyed Low Carbon Steel, Xianglong Yu, Zhengyi Jiang, Daijun Yang, Dongbin Wei, Quan Yang
Faculty of Engineering - Papers (Archive)
Precipitation behavior of magnetite particles in the thermal grown oxide scale during isothermal cooling of microalloyed low carbon steel was studied using scanning electron microscopy (SEM) and thin film X-ray. The oxide scale was generated from Gleeble 3500 Thermal-Mechanical Simulator connected with a humid air generator, to simulate 550 and 450°C isothermal treatments. Several types of magnetite precipitates were observed during different cooling processes with respect to the possible mechanisms of precipitation have been discussed. It is found that magnetite particles is as a result of pro-eutectoid precipitation from oxygen-rich wustite, and also as a product of the partial decomposition …
Observation Of Precipitation Evolution In Fe-Ni-Mn-Ti-Al Maraging Steel By Atom Probe Tomography, E V. Pereloma, R.A. Stohr, M.K Miller, S P. Ringer
Observation Of Precipitation Evolution In Fe-Ni-Mn-Ti-Al Maraging Steel By Atom Probe Tomography, E V. Pereloma, R.A. Stohr, M.K Miller, S P. Ringer
Faculty of Engineering - Papers (Archive)
We describe the full decomposition sequence in an Fe-Ni-Mn-Ti-Al maraging steel during isothermal annealing at 550 °C. Following significant pre-precipitation clustering reactions within the supersaturated martensitic solid solution, (Ni,Fe)3Ti and (Ni,Fe)3(Al,Mn) precipitates eventually form after isothermal aging for ~60 seconds. The morphology of the (Ni,Fe)3Ti particles changes gradually during aging from predominantly plate-like to rod-like, and, importantly, Mn and Al were observed to segregate to these precipitate/matrix interfaces. The (Ni,Fe)3(Al,Mn) precipitates occurred at two main locations: uniformly within the matrix and at the periphery of the (Ni,Fe)3Ti particles. We relate …
Effect Of Nb And Mo Additions On The Microstructure And Mechanical Properties Of Thermomechanically Processed And Bake Hardened Cmnsi Trip Steel, E V. Pereloma, I. B. Timokhina, M. K. Miller
Effect Of Nb And Mo Additions On The Microstructure And Mechanical Properties Of Thermomechanically Processed And Bake Hardened Cmnsi Trip Steel, E V. Pereloma, I. B. Timokhina, M. K. Miller
Faculty of Engineering - Papers (Archive)
Bake hardening of steels during paint baking of an automotive body could result in an increase of their strength. In this work, the effect of pre-straining and bake-hardening on the microstructure and mechanical properties has been investigated in thermomechanically processed CMnSi Transformation-Induced Plasticity (TRIP) steels with and without additions of Nb and Mo. The steels were characterised before and after bake hardening at 180oC for 30 min. by transmission electron microscopy (TEM), X-ray diffraction (XRD), atom probe tomography (APT), and tensile tests. The microstructure of the thermomechanically processed (TMP) TRIP steels consisted of polygonal ferrite, bainite, retained austenite and martensite. …
Nanoscale Characterisation Of Advanced High Strength Steels Using Atom Probe Tomography, E V. Pereloma, I. B. Timokhina, P. D. Hodgson, M. K. Miller
Nanoscale Characterisation Of Advanced High Strength Steels Using Atom Probe Tomography, E V. Pereloma, I. B. Timokhina, P. D. Hodgson, M. K. Miller
Faculty of Engineering - Papers (Archive)
Over the last few years, there has been significant interest in the design of new high strength steels with complex microstructures and the manipulation of their properties at the nanoscale. Understanding the effects of alloying additions on the nanoscale level is essential for tailoring the steel composition and properties for a specific product requirement. Atom probe tomography plays an important role in the characterisation of the microstructural features at the atomic level. This powerful technique has been used for the direct experimental observations of early stages of phase transformations, clustering, fine precipitation, atmospheres around dislocations and segregation to boundaries. An …
Nanostructural Engineering Of Steel, P. D. Hodgson, I. B. Timokhina, H. Beladi, I. Sabirov, E V. Pereloma
Nanostructural Engineering Of Steel, P. D. Hodgson, I. B. Timokhina, H. Beladi, I. Sabirov, E V. Pereloma
Faculty of Engineering - Papers (Archive)
The concept of microstructural engineering of steels is well established and is the basis for a wide range of processes and products. Recently, though, there has been increasing emphasis in developing microstructures that have submicron length scales and also in understanding in far greater detail the structures and solute effects that are occurring at the nanoscale. In this review it is proposed that we are heading towards the situation where we are applying nanostructural engineering concepts in the development of new steels. A range of examples are given as well as a discussion of the potential impact of new processing …
In-Situ Observation Of Sulfide Precipitation In A Low-Carbon, Titanium Alloyed Steel, Sima Aminorroaya-Yamini, Rian J. Dippenaar, Mark H. Reid
In-Situ Observation Of Sulfide Precipitation In A Low-Carbon, Titanium Alloyed Steel, Sima Aminorroaya-Yamini, Rian J. Dippenaar, Mark H. Reid
Faculty of Engineering - Papers (Archive)
Removal of inclusions is of greatsignificance to steelmakers and the scientific principles underpinning inclusion removal has been the subject of numerous investigations in the past and during the last few decades, it has become increasingly obvious that inclusions can be utilized as an effective tool for the control of microstructure1 . Manganese sulfide precipitates are known to crystallize and precipitate preferentially in interdendritic regions during solidification, due to segregation of manganese and sulphur2 and these inclusions have traditionally been used for the dual purpose of improving the machinability and controlling of grain structure in steel. Small MnS particles restrain grain …