With appropriate electropulsing parameters, the microstructure of steels can be manipulated towards a state that possesses favourable physical, mechanical and chemical properties. This work demonstrates the application of designed electropulsing to pearlitic steel, transformation induced plasticity steel, austenite stainless steel and clean steel in order to generate novel microstructures that are difficult to achieve by other conventional thermomechanical processes. The principles for the design of electropulsing processing have been discussed. The method is particularly suitable for fabrication of the advanced multiphase and multicomponent alloys.

of pearlite are extensively used in various engineering and commercial applications since they possesses a good combination of strength and ductility as well as other useful material properties such as corrosion resistance, wear resistance, weldability and machinability. The stress-strain behaviours of ferritic-pearlitic steels strongly depend on its constituent phases: ferrite governs the ductility whereas pearlite phase controls the strength [1]. The relationship between microstructure and mechanical properties of these steels have been investigated by many researchers [1,2,3]. Various colonies of pearlite have different lamellae orientations. These cementite lamellae are frequently paralleled and curved and the interlamellar spacing varies in size from colony to colony [2]. Hence, pearlite microstructure can be tailored by variation of the interlamellar spacing which directly affects the strength [3].It is known that the application of electric current pulses to metallic materials affects materials plasticity [4], recrystallization [5], structure relaxation [6], casting microstructure [7,8] and fatigue life [9]. For Fe-3wt% Si alloys, electropulse has been found to promote the Goss-texture development during recrystallization [11,23]. Theoretically, electropulse is found affecting the kinetic barrier and free energy sequence of phases. The former includes the phase transformation at a lower than ordinary temperature [12] and the enhanced diffusivity [17]. The latter includes the electropulseinduced new phase [14] and new microstructure formations [15]. In the present work, electropulse-induced cementite plates rotation in ferritic-pearlitic steel was observed. This reveals a new mechanism that has not been covered in literature. Application of Electropulsing in the process of ferritic-pearlitic steel may provide a new way to enhance mechanical properties by altering the pearlite transformation and microstructure.The steel was prepared via the conventional ingot metallurgical routine and the chemical composition in weight percentage of the alloy was found to be 0.14 C-1.0 Si-2.1 Mn-0.03 Al-0.025 Nb and balance iron. The ingot was rolled at 800• C to Preprint submitted to Elsevier April 27, 2015 a sheet with 2.64 mm thickness and then chilled slowly in furnace. Its microstructure at ambient temperature consists of mainly the polycrystalline ferrite grains and a small amount of cementite scattered among the ferrite. The sheet was cut into many 30 mm(longitudinal length) × 3.42 mm (width) × 2.64 mm (thickness) samples and grouped randomly for subsequent electropulsing treatment. The electropulse was generated by an Avtech AV-108F-B-P Current Pulser which converted the direct current into pulsed current. The direct current power source has standard output power of 80 watts and standard output electric potential of 20 volts. The pulse width, peak current intensity, pulse frequency and pulse trigger mode are programmable. The testing steel sample was connected with two copper electrodes from both ends to form a curr...

Effect of Ni alloying on the microstructural evolution and mechanical properties of two duplex lightweight steels during different annealing temperatures : experiment and phase-field simulation. Acta Materialia.