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Ferrite 5.2Modified heat treatment cycle-1 Since impact was a requirement and test certificate values for this heat had showed lower impact energy after hardening heat treatment at 10000-10300C, in order to refine the microstructure and control grain growth[1] for improving impact energy,modified heat treatment was suggested; Hardening at 960-990°C for 1 hour- Oil quenchingto reduce grain growth [3] followed by tempering at 740-780°C for 1 hour-Air cooling outside furnace.
Hence it becomes essential to minimize carbide and nitride precipitate formation along ferrite-ferrite and ferrite-martensite grain boundaries in order to get good toughness values [4].
The number and distribution of precipitates was extremely lowin ferrite matrix (as shown in Fig.3a & b).Charpy Impact test on the above specimens at room temperature showed high impact energy of the order of 82J,70J& 65J.
Very thin and very less number of stringers andcarbide precipitates, thus impact energy is high.
It should not form carbides on the grain boundaries.

Intorduction Ion implantation, as a method of targeted influence on the structure and properties of materials, is still insufficiently studied in a number of aspects.
Nevertheless, to date, a fairly extensive experimental material has been accumulated, which with sufficient certainty confirms that in the process of ion implantation a significant number of so-called radiation defects, surface sputtering, changes and displacement of structural elements, etc. occur. [1-8] The microstructure of implanted metals and alloys is determined by the processes occurring in any supersaturated solid solution with some specific effect’s characteristic of the implanted metal [9-15]: 1) radiation-enhanced diffusion, which increases the rate of diffusion-limited excretions; 2) reverse dissolution, in which the atoms of the precipitates pass into the main matrix by a cascade of ionic displacements; 3) disordering dissolution, in which atoms near the outer surface of the precipitate can pass into solution as a result of short-term softening; 4) fragmentation of precipitates due to cutting by dislocations formed during the accumulation of implanted defects; 5) local
Microstructure of alloy 1420 after implantation with nitrogen ions With a more detailed study of the surface layer of this alloy on a scanning electron microscope (Figure 2), several sublayers are observed: - the actual implanted layer (white, non-etched); - a dark area without sharp outlines of borders; - a zone of rounded grains; - a zone of elongated grains with etched boundaries.
Microstructure of the surface layer of alloy 1420 after ion implantation of nitrogen: a - white non-etched layer; b - dark zone without outlines of grain boundaries; c - a zone of round grains; d - a zone of elongated grains with etched boundaries.

Results of the study showed that the microstructure of steel С355 in the state of delivery is a ferrite-pearlite structure in which ferrite grains are predominantly of a polygonal shape with an average size of the 9th number according to GOST 5639-82.
For example, when plasma cutting of a sheet of steel С355 of thickness 12 mm there is observed at first a recrystallization area with an average austenitic grain of size 20 microns in the HAZ of edge.
A bainitic structure is formed inside this grain.
Then, there is an area of a partial recrystallization with a foliated ferrite-bainitic structure and an average ferritic grain size of 11 microns.
The average grain size of ferrite in the partially transformed zone is 16 microns.

In actual, the Co-Re system has been seldom investigated in the past and only a small number of articles exist.
In both cases, additional strengthening through solid solution effects of Re and strengthening of grain boundaries by B and Zr is combined.
A number of model alloys: divided into two groups – i) alloys for studying strengthening behaviour and ii) alloys for studying oxidation behaviour were prepared by vacuum arc melting either as small buttons (100 g) or as cast bars (12 x 12 x 70 mm3).
Co-17Re-23Cr-2.6C + 200 -1000 ppm B and 500 – 2000 ppm Zr Alloys with B and Zr additions for grain boundary strengthening Model alloys for Oxidation: 1.
In the CoRe-ref. alloy the s phase is distributed as large (5 to 10 µm) particles at the grain boundaries and within the grains.

An appropriate detector material can be selected from a large number of publications on various alloys primarily binary alloys of Nickel and Iron and ternary versions with Cobalt.
In order to increase the number of samples per sputter run of sputtered NiFe films, a substrate holder was used which could accommodate four substrates.
The tendency for a50 to increase rapidly above approximately 250 oC suggests that the grain growth is the major influence in the increasing value.
Hoffmann [19] has shown theoretically that a50 should increase with mean grain diameter. .......
Paul and Hanson [22] have suggested that the amount of oxygen present in medium vacuum systems inhibit the coalescence and grain growth within the films deposited.

Increasing the temperature up to 1400°C [Fig. 2 (c)] shows no porosity and clear grain boundaries of particles.
When the temperature increased, the particles sintered and pore on grain boundaries reduced by solid-state diffusion [14].
Besides, sintering temperature supplies driving energy for grain growth and strongly affects grain size [17].
Acknowledgement This research was funded by Universiti Sains Malaysia Short Term Grant with the grant number 304/PPSG/6315034 and Research University Grant (RUI) with the grant number 1001/PPSG/8012371.
Keul, Zirconia ceramics, their contrast ratio and grain size depending on sintering parameters, Dental Materials Journal, 33(5), (2014) 591–598

The number of new dislocations strongly depends on the initial dislocation density of the material.
When melt temperature increases, TEM observations of the different strips have shown a decrease of grain size, associated with a cellular precipitation of a higher amount of Ti2Ni (Fig. 6).
Relatively high elongation recovery can find its origin in the columnar grain orientation.
Despite of a relatively high cooling rate, which is realized in TRC technique, almost 66% of the grains were oriented along the fibre <001> texture component and 18% with {001}<100> sheet texture component.
It means that only less than 16% of the grains were randomly oriented.

Increasing the current densities to 250 A/mm2 and 350 A/mm2, the fracture surfaces appear obviously ductile, with the individual tungsten grains deformed to knife edges.
A large number of studies have shown that electroplastic effect is a kind of comprehensive effect, it contains the side effect of skin, pinch, Joule heating and the pure electroplastic effect.
During the drawing process the wires undergo severe plastic deformation that grains elongate in the axial direction.
This result may be induced by the increasing current density along the grain boundaries during tension, local heating can occur along phase boundaries [11-13].
Cao, Influence of grain size and grain boundaries on the thermal and mechanical behavior of 70/30 brass under electrically-assisted deformation, Mater.

Since corrosion resistance of Ta was much higher than that of Zr[19], Zr was preferentially corroded, and a large number of lamellar Ta structures appeared in Fig. 4(a)-(d).
In Fig. 4(a), the whole area had the structure, and the lamellar Ta in each grain is arranged neatly, but there was a difference in the growth direction, which may be related to the different preferred orientation of Ta in different grains.
And the grain size was between 10 and 20 μm, slightly larger than the particle size, which was related to the grain growth during the sintering process.
Under the action of tensile stress, the crack was preferentially formed at the interface and extended along the grain boundary, resulting in a lower tensile strength and elastic modulus than that of pure metal.
It can be seen from Fig. 6(a) that MG-63 cells grew well on the Ta-Zr alloy after 4 hours culture and a large number of pseudopods surrounded cells.

Amount of shielding gas and number of passes are taken as variables in welding conditions.
There were a number of trial runs carried out to make the weld bead on plates before going to the actual experiments.
It can be recognized that the grain size was large and equaxid in the case of base metal and it became elongated and smaller in the affected zone.
The smallest grains were found in the welding zone especially near the heat affected zone interface.
The nucleation rate was very high and consequently more grains were formed but the growths of these grains were restricted by each other forming small grains (high cooling rate).