Understanding the behavior of advanced high-strength steels using atom probe tomography

The key evidence for understanding the mechanical behavior of advanced high strength steels was provided by atom probe tomography (APT). Chemical overstabilization of retained austenite (RA) leading to the limited transformation-induced plasticity (TRIP) effect was deemed to be the main factor responsible for the low ductility of nanostructured bainitic steel. Appearance of the yield point on the stress-strain curve of prestrained and bake-hardened transformationinduced plasticity steel is due to the unlocking from weak carbon atmospheres of newly formed during prestraining dislocations.

Application of advanced analytical techniques to study structure-property relationship of hot rolled high strength low alloy steel

The microstructure-property relationship in conventional high strength low alloy (HSLA) steel was evaluated using data obtained from transmission electron microscopy (TEM) and atom probe tomography (APT). Atom probe tomography allowed the characterisation of fine TiC particles with average radius of 3±1·2 nm that were not observed by TEM. The increase in the yield strength of steel due to the presence of fine precipitates was calculated to be 128 MPa.

Possible electrical double-layer contribution to the equilibrium thickness of intergranular Glass films in polycrystalline ceramics

The plausibility of the entropic repulsion of electrical double layers acting to stabilize an equilibrium thickness of intergranular glass films in polycrystalline ceramics is explored. Estimates of the screening length, surface potential, and surface charge required to provide a repulsive force sufficiently large to balance the attractive van der Waals and capillary forces for observable thicknesses of intergranular film are calculated and do not appear to be beyond possibility. However, it has yet to be established whether crystalline particles in a liquid-phase sintering medium possess an electrical double layer at high temperatures. If they do, such a surface charge layer may well have important consequences not only for liquid-phase sintering but also for high-frequency electrical properties and microwave sintering of ceramics containing a liquid phase.

Springback data from stamping and simulating the forming of advanced high strength steel

This dataset is comprised of a spreadsheet of simulation result files, cross-section geometries of stamped parts, strain results of cross-section of stamped parts, simulation data (strain stress displacement energies), and variation data of material properties of a single coil. This data is a collection of both experimental and simulation results from industrial and laboratory stamping of advanced high strength steels (AHSS). The steels that were stamped were a typical high-strength low-alloy (HSLA) steel, a transformation-induced plasticity (TRIP) steel, a super HSLA steel, and a dual phase (DP) steel. The selected part was an automatic Ford Falcon front cross-member component using the Ford Geelong stamping plant. The variation of the material and stamped parts was also collected.

Application of advanced experimental techniques for the microstructural characterization of nanobainitic steels

A 0.79C-1.5Si-1.98Mn-0.98Cr-0.24Mo-1.06Al-1.58Co (wt%) steel was isothermally heat treated at 350°C bainitic transformation temperature for 1 day to form fully bainitic structure with nano-layers of bainitic ferrite and retained austenite, while a 0.26C-1.96Si-2Mn-0.31Mo (wt%) steel was subjected to a successive isothermal heat treatment at 700°C for 300 min followed by 350°C for 120 min to form a hybrid microstructure consisting of ductile ferrite and fine scale bainite. The dislocation density and morphology of bainitic ferrite, and retained austenite characteristics such as size, and volume fraction were studied using Transmission Electron Microscopy. It was found that bainitic ferrite has high dislocation density for both steels. The retained austenite characteristics and bainite morphology were affected by composition of steels. Atom Probe Tomography (APT) has the high spatial resolution required for accurate determination of the carbon content of the bainitic ferrite and retained austenite, the solute distribution between these phases and calculation of the local composition of fine clusters and particles that allows to provide detailed insight into the bainite transformation of the steels. The carbon content of bainitic ferrite in both steels was found to be higher compared to the para-equilibrium level of carbon in ferrite. APT also revealed the presence of fine C-rich clusters and Fe-C carbides in bainitic ferrite of both steels.

Effect of composition and processing parameters on the formation of nano-bainite in advanced high strength steels

The nano-bainitic microstructures were compared in a 0.79C-1.5Si-1.98Mn-0.24Mo-1.06Al (wt%) steel after isothermal heat-treatment and a Fe-0.2C-1.5Mn-1.2Si-0.3M0-0.6Al-0.02Nb (wt%) steel after controlled thermo-mechanical processing. The microstructure for both steels consisted of bainite. The microstructural characteristics of bainite, such as the morphology of the nano-bainite and thicknesses of bainitic ferrite and retained austenite layers, as a function of steel composition and processing was studied using transmission electron microscopy (TEM). It was found that the nano-bainitic structure can be formed in the low alloy steel through thermomechanical processing. Atom probe tomography (APT) was employed as a powerful technique to determine local composition distributions in three dimensions with atomic resolution. The important conclusions from the APT research were that the carbon content of bainitic ferrite is higher than expected from paraequilibrium level of carbon in ferrite for both steels and that Fe-C clusters and fine particles are formed in the bainitic ferrite in both steels despite the high level of Si.

Current issues in management (Advanced Diploma of Management) TF/109/GEN/160/LP learner's resource

Study guide for TAFE management unit in Victoria.

Advanced vascular access workshop for dialysis nurses : a three-year review

There is increased awareness regarding the benefits of ultrasound for vascular access surveillance and guided cannulation in haemodialysis. However, finding time to train staff whilst working within the clinical setting is challenging. In 2009 a workshop was introduced in Victoria to provide a platform for nursing staff to learn advanced skills in surveillance and cannulation in a safe, supportive environment. The workshop covered topics such as: assessment and cannulation; surgical perspectives in vascular access; radiological perspectives in vascular access; surveillance and monitoring; cannulation competency package; antegrade/antegrade cannulation; and introduction to ultrasound plus five hours of practical sessions. Feedback from the workshop over the past three years has been positive, and staff have benefited from the both the theoretical and clinical components of the workshop. The success of this workshop highlights the demand for continuing education within the renal workforce.

Management of advanced neuroendocrine tumors with hepatic metastasis

Neuroendocrine tumors (NETs) in general and specifically these gastroenteropancreatic-neuroendocrine tumors often present a considerable diagnostic and therapeutic challenge, especially those that behave in an aggressive fashion. The majority of tumors are diagnosed at a stage that the only curative treatment, radical surgical intervention, is no longer an option and thus long-term therapy with somatostatin analogs is focused on symptom amelioration and in the improvement of quality of life. Although biotherapy is currently the most efficient treatment to achieve palliation, conventional chemotherapy may have some utility in undifferentiated or highly proliferating neuroendocrine carcinomas and pancreatic NETs. Hepatic metastases, depending on size, location, and number may be amenable to surgical resection or radiofrequency ablation. If surgery is not feasible, embolization either alone (bland), in combination with chemotherapeutic agents, or using radioactive microspheres can be used. Peptide receptor targeted radiotherapy using radiolabeled octapeptide analogs (⁹⁰Yttrium or ¹⁷⁷Lutetium-octreotide) may lead to reduction in tumor size, but in most circumstances has a tumor stabilizing effect. A variety of antiangiogenesis and growth factor-targeted agents have been evaluated, but to date, the results have failed to meet our expectations.