Speaker
Description
Metallurgical technologies of the XXI century should possess the following characteristics simultaneously: (i) low cost and energy consumption, (ii) high strength, ductility and weldability of the manufactured product, (iii) commercial sustainability at low production volumes, (iv) flexibility of equipment for quick change to new product geometry and steel composition. The closest manufacturing schemes, amongst the currently operating, to what we would require in future are those that are based on strip casting. However, these technologies may have some drawbacks, such as too thin cast strip thickness and difficulties to control the strength-ductility relationship. Recently, we suggested a novel steel technology based on casting of 10 mm thick strip, followed by austenite conditioning, accelerated cooling and warm deformation. This presentation will summarise the results of laboratory modelling of the technology in Gleeble. With respect to processing parameters and steel composition (in particular, contents of Ti, Nb, Mo, Mn and Cr), the following property levels have been achieved: 740-950 MPa of the yield stress, 900-1100 MPa of tensile strength and 17-24 % of elongation to failure. These values are quite remarkable for so minor microalloying element additions as 0.095C-0.012Ti, 0.15C-0.015Nb or 0.08C-0.2(Mo+Nb+Ti) and moderate total deformations as 2.3-5.3 mm. The microstructural investigation has shown that grain refinement, solid solution strengthening and work hardening (development of diverse dislocation structure, low angle boundaries, and shear bands) governed the formation of mechanical properties.
| Speaker Country | Australia |
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