ABSTRACT Friction stir welding (FSW) process is an emerging solid state joining process in which ... more ABSTRACT Friction stir welding (FSW) process is an emerging solid state joining process in which the material that is being welded does not melt and recast. This process uses a non-consumable tool to generate frictional heat in the abutting surfaces. The welding parameters such as tool rotational speed, welding speed, axial force, etc., and tool pin profile play a major role in deciding the weld quality. Friction stir tool plays a major role in friction stir welding process. In this investigation, it is tried to evaluate the effect of tool pin thread and tool shoulder curvature on FSW zone formation in AA6061 aluminium alloy. In this regard, six different tool pin geometries (threadless triangular pin with/without conical shoulder, threaded triangular pin with conical shoulder, threadless square pin with/without conical shoulder, threaded square pin with conical shoulder) are used to fabricate the joints. The formation of FSP zones are analyzed macroscopically. Tensile properties of the joints are evaluated and correlated with the FSP zone formation. Consequently, it is obtained that welding creates a higher quality compared to other tool pin profiles using the square tool with curved shoulder and having threaded pin.
ABSTRACT In this study, the effects of tungsten on microstructure and wear performance of Fe-Cr-C... more ABSTRACT In this study, the effects of tungsten on microstructure and wear performance of Fe-Cr-C claddings were evaluated. In this regard, tungsten inert gas surfacing process was employed to deposit Fe-Cr-C and Fe-Cr-C-W hardfacing alloys on plain carbon steel substrate using preplaced powders. Phase composition, microstructure, and wear behavior of clad layers were investigated using X-ray diffraction analysis, optical and scanning electron microscopy, and reciprocating wear tests, respectively. The claddings were well bonded to the substrate and showed a uniform microstructure. Cr7C3 and WC carbides were detected in the deposited layers. Further investigations indicated that the hardness and wear resistance can be improved by adding tungsten into Fe-Cr-C hardfacing alloys.
ABSTRACT Friction stir welding (FSW) process is an emerging solid state joining process in which ... more ABSTRACT Friction stir welding (FSW) process is an emerging solid state joining process in which the material that is being welded does not melt and recast. This process uses a non-consumable tool to generate frictional heat in the abutting surfaces. The welding parameters such as tool rotational speed, welding speed, axial force, etc., and tool pin profile play a major role in deciding the weld quality. Friction stir tool plays a major role in friction stir welding process. In this investigation, it is tried to evaluate the effect of tool pin thread and tool shoulder curvature on FSW zone formation in AA6061 aluminium alloy. In this regard, six different tool pin geometries (threadless triangular pin with/without conical shoulder, threaded triangular pin with conical shoulder, threadless square pin with/without conical shoulder, threaded square pin with conical shoulder) are used to fabricate the joints. The formation of FSP zones are analyzed macroscopically. Tensile properties of the joints are evaluated and correlated with the FSP zone formation. Consequently, it is obtained that welding creates a higher quality compared to other tool pin profiles using the square tool with curved shoulder and having threaded pin.
ABSTRACT Three Fe-based alloys, namely 55Fe39Cr6C, 49Fe39Cr6C6Si, and 45Fe39Cr6C10Si (wt.%), were... more ABSTRACT Three Fe-based alloys, namely 55Fe39Cr6C, 49Fe39Cr6C6Si, and 45Fe39Cr6C10Si (wt.%), were fabricated on AISI St52 using a tungsten-inert gas (TIG) heat source. Microstructure, microhardness, and electrochemical corrosion behavior of the TIG clad composite coatings were investigated. It was found that as-deposited coatings consisted of higher volume fractions of carbides (Cr7C3). Potentiodynamic polarization studies in the 3.5 wt.% NaCl solution showed that the corrosion resistance of the substrate was remarkably improved by TIG surface coating (TSC) with 55Fe39Cr6C and 49Fe39Cr6C6Si, while 45Fe39Cr6C10Si had a lower effect on this same property. The formation of silicides (Fe3Si) in the clad with 45Fe39Cr6C10Si was taken as the reason for the reduced corrosion resistance observed as compared to those of the other clads.
In the present study, the surface of St52 steel was alloyed with
preplaced Fe-Cr-C and Fe-Cr-Nb-C... more In the present study, the surface of St52 steel was alloyed with preplaced Fe-Cr-C and Fe-Cr-Nb-C powders by using a tungsten-inert gas (TIG) heat source. The microstructure and phase composition of the alloyed surfaces were investigated using optical microscopy, scanning electron microscopy (SEM) and X-ray diffraction. Microhardness measurements were performed across the alloyed zone. The tribological behaviour of the coatings was evaluated using dry sliding wear tests at room temperature. It was found that the as-deposited coatings consisted of high volume fraction of carbides (Cr7C3, NbC). The Nb free and Nb-contained clad coatings both exhibited an excellent wear resistance compared to 0.22% C carbon steel under dry sliding wear tests. The wear resistance of Nb-contained clad coating was higher than that of the Nb-free clad coating because the hard carbide NbC was distributed in clad coating which increased the wear resistance of clad
ABSTRACT Friction stir welding (FSW) process is an emerging solid state joining process in which ... more ABSTRACT Friction stir welding (FSW) process is an emerging solid state joining process in which the material that is being welded does not melt and recast. This process uses a non-consumable tool to generate frictional heat in the abutting surfaces. The welding parameters such as tool rotational speed, welding speed, axial force, etc., and tool pin profile play a major role in deciding the weld quality. Friction stir tool plays a major role in friction stir welding process. In this investigation, it is tried to evaluate the effect of tool pin thread and tool shoulder curvature on FSW zone formation in AA6061 aluminium alloy. In this regard, six different tool pin geometries (threadless triangular pin with/without conical shoulder, threaded triangular pin with conical shoulder, threadless square pin with/without conical shoulder, threaded square pin with conical shoulder) are used to fabricate the joints. The formation of FSP zones are analyzed macroscopically. Tensile properties of the joints are evaluated and correlated with the FSP zone formation. Consequently, it is obtained that welding creates a higher quality compared to other tool pin profiles using the square tool with curved shoulder and having threaded pin.
ABSTRACT In this study, the effects of tungsten on microstructure and wear performance of Fe-Cr-C... more ABSTRACT In this study, the effects of tungsten on microstructure and wear performance of Fe-Cr-C claddings were evaluated. In this regard, tungsten inert gas surfacing process was employed to deposit Fe-Cr-C and Fe-Cr-C-W hardfacing alloys on plain carbon steel substrate using preplaced powders. Phase composition, microstructure, and wear behavior of clad layers were investigated using X-ray diffraction analysis, optical and scanning electron microscopy, and reciprocating wear tests, respectively. The claddings were well bonded to the substrate and showed a uniform microstructure. Cr7C3 and WC carbides were detected in the deposited layers. Further investigations indicated that the hardness and wear resistance can be improved by adding tungsten into Fe-Cr-C hardfacing alloys.
ABSTRACT Friction stir welding (FSW) process is an emerging solid state joining process in which ... more ABSTRACT Friction stir welding (FSW) process is an emerging solid state joining process in which the material that is being welded does not melt and recast. This process uses a non-consumable tool to generate frictional heat in the abutting surfaces. The welding parameters such as tool rotational speed, welding speed, axial force, etc., and tool pin profile play a major role in deciding the weld quality. Friction stir tool plays a major role in friction stir welding process. In this investigation, it is tried to evaluate the effect of tool pin thread and tool shoulder curvature on FSW zone formation in AA6061 aluminium alloy. In this regard, six different tool pin geometries (threadless triangular pin with/without conical shoulder, threaded triangular pin with conical shoulder, threadless square pin with/without conical shoulder, threaded square pin with conical shoulder) are used to fabricate the joints. The formation of FSP zones are analyzed macroscopically. Tensile properties of the joints are evaluated and correlated with the FSP zone formation. Consequently, it is obtained that welding creates a higher quality compared to other tool pin profiles using the square tool with curved shoulder and having threaded pin.
ABSTRACT Three Fe-based alloys, namely 55Fe39Cr6C, 49Fe39Cr6C6Si, and 45Fe39Cr6C10Si (wt.%), were... more ABSTRACT Three Fe-based alloys, namely 55Fe39Cr6C, 49Fe39Cr6C6Si, and 45Fe39Cr6C10Si (wt.%), were fabricated on AISI St52 using a tungsten-inert gas (TIG) heat source. Microstructure, microhardness, and electrochemical corrosion behavior of the TIG clad composite coatings were investigated. It was found that as-deposited coatings consisted of higher volume fractions of carbides (Cr7C3). Potentiodynamic polarization studies in the 3.5 wt.% NaCl solution showed that the corrosion resistance of the substrate was remarkably improved by TIG surface coating (TSC) with 55Fe39Cr6C and 49Fe39Cr6C6Si, while 45Fe39Cr6C10Si had a lower effect on this same property. The formation of silicides (Fe3Si) in the clad with 45Fe39Cr6C10Si was taken as the reason for the reduced corrosion resistance observed as compared to those of the other clads.
In the present study, the surface of St52 steel was alloyed with
preplaced Fe-Cr-C and Fe-Cr-Nb-C... more In the present study, the surface of St52 steel was alloyed with preplaced Fe-Cr-C and Fe-Cr-Nb-C powders by using a tungsten-inert gas (TIG) heat source. The microstructure and phase composition of the alloyed surfaces were investigated using optical microscopy, scanning electron microscopy (SEM) and X-ray diffraction. Microhardness measurements were performed across the alloyed zone. The tribological behaviour of the coatings was evaluated using dry sliding wear tests at room temperature. It was found that the as-deposited coatings consisted of high volume fraction of carbides (Cr7C3, NbC). The Nb free and Nb-contained clad coatings both exhibited an excellent wear resistance compared to 0.22% C carbon steel under dry sliding wear tests. The wear resistance of Nb-contained clad coating was higher than that of the Nb-free clad coating because the hard carbide NbC was distributed in clad coating which increased the wear resistance of clad
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preplaced Fe-Cr-C and Fe-Cr-Nb-C powders by using a tungsten-inert gas (TIG) heat source. The microstructure and phase composition of the alloyed surfaces were investigated using optical microscopy, scanning electron microscopy (SEM) and X-ray diffraction. Microhardness measurements were performed across the alloyed zone. The tribological behaviour of the coatings was evaluated using dry sliding wear tests at room temperature. It was found that the as-deposited coatings consisted of high volume fraction of carbides (Cr7C3, NbC). The Nb free and Nb-contained clad coatings both exhibited an
excellent wear resistance compared to 0.22% C carbon steel under dry sliding wear tests. The wear resistance of Nb-contained clad coating was higher than that of the Nb-free clad coating because the hard carbide NbC was distributed
in clad coating which increased the wear resistance of clad
preplaced Fe-Cr-C and Fe-Cr-Nb-C powders by using a tungsten-inert gas (TIG) heat source. The microstructure and phase composition of the alloyed surfaces were investigated using optical microscopy, scanning electron microscopy (SEM) and X-ray diffraction. Microhardness measurements were performed across the alloyed zone. The tribological behaviour of the coatings was evaluated using dry sliding wear tests at room temperature. It was found that the as-deposited coatings consisted of high volume fraction of carbides (Cr7C3, NbC). The Nb free and Nb-contained clad coatings both exhibited an
excellent wear resistance compared to 0.22% C carbon steel under dry sliding wear tests. The wear resistance of Nb-contained clad coating was higher than that of the Nb-free clad coating because the hard carbide NbC was distributed
in clad coating which increased the wear resistance of clad