Correlation of microstructure and fracture toughness in high-chromium white iron hardfacing alloys

Lee, Sunghak; Choo, Seong-Hun; Kim, Nack J.; Baek, Eung-Ryul; Ahn, Soonho

doi:10.1007/bf02595637

Cited by 20 publications

(9 citation statements)

References 19 publications

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“…Analyzing the microstructure of the alloys, it is suggested that the toughness was controlled mainly by the amount of austenite in the matrix, thereby yielding better toughness in hardfacing alloy 750, which has an austenitic matrix. [3] Furthermore, although this alloy has an austenitic matrix, its wear resistance is slightly higher than alloy HCO containing large primary M 7 C 3 carbides.…”

Section: Hardness and Wear Resistancementioning

confidence: 99%

“…Because carbides are prone to fall off from a matrix during the wear process, the resulting volume loss of material from the surface can often be more intense, resulting in severe wear. [3] Another way to improve the wear resistance of the FeCr-C alloys, together with the toughness needed to withstand repeated impact, is to add very strong carbide forming elements such as Nb, V, W, and Ti in their composition in order to obtain very hard MC-type carbides, which are harder but finer than chromium carbides. In general, if there is a uniform distribution of these carbides, and if they are closely spaced, abrasives cannot effectively penetrate into the matrix phase, leading to higher wear resistance and toughness.…”

Section: Introductionmentioning

confidence: 99%

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The Relationship between the Microstructure and Abrasive Resistance of a Hardfacing Alloy in the Fe-Cr-C-Nb-V System

Corrêa

Alcântara

Tecco

et al. 2007

Metall Mater Trans A

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The relationship between abrasive wear resistance and microstructure of a hardfacing alloy based on the Fe-Cr-C-Nb-V system was investigated. This material was developed for cladding, by an open arc welding technique, of components subjected to severe abrasive wear. The work undertaken included the solidification study, microstructural characterization, and abrasion testing. Microstructural examinations of hardfaced layer showed that the microstructure of the alloy consisted of a large volume fraction of primary niobium carbides randomly dispersed in a metastable austenitic matrix containing fine M 3 C carbides and ''islands'' of eutectic mixture of c/M 7 C 3 . Energy dispersive X-ray analysis results showed that V preferentially partitioned into the NbC and M 3 C phases. In comparison with the conventional high carbon/high chromium hardfacing alloy with higher hardness, a Fe-Cr-C-Nb-V hardfacing alloy exhibited improved abrasive wear resistance and a microstructure with higher toughness.

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Section: Hardness and Wear Resistancementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

The Relationship between the Microstructure and Abrasive Resistance of a Hardfacing Alloy in the Fe-Cr-C-Nb-V System

Corrêa

Alcântara

Tecco

et al. 2007

Metall Mater Trans A

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“…These alloys contain various types of carbides mainly M 7 C 3 types although other variety of carbides such as M 6 C and M 3 C are also available. The sizes of primary carbides are between 50 and 100 μm whereas the sizes of eutectic carbides are generally less than 10 μm [47]. Matrix surrounding these carbides can be pearlitic, austenitic or martensitic.…”

Section: Cast Ironsmentioning

confidence: 99%

“…In-situ observation of the fracture process showed that microcracks were initiated at complex carbides and that shear bands were formed between them, leading to ductile fracture. The hardness, wear resistance and fracture toughness of the hardfacing alloys reinforced with complex carbides were improved in comparison with high-chromium whiteiron hardfacing alloys, because of the homogeneous distribution of hard and fine complex carbides in the bainitic matrix [75].…”

Section: Sliding Wearmentioning

confidence: 99%

Hardfacing for Wear, Erosion and Abrasion

Badisch

Roy

2013

Surface Engineering for Enhanced Performance Against Wear

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Weld overlay coatings also known as hardfacing is a method which involves solidification for applied coatings. This method is as old as welding process and was first applied by J.W. Spencer in 1896. This technique offers unique advantages over other processes in that the overlay/substrate weld provides a metallurgical bond which is not susceptible to spallation and can easily be applied free of porosity and other defects. Weld deposits can have a thickness as high as 10 mm. Hardfacing process can be carried out easily even in on site. The process is also extremely versatile as a large variety of materials can be deposited for protection against degradation.Weld overlay coatings can be classified under four different categories. These are (1) surface cladding where a thick layer of materials is applied and the overlay layer can have completely different composition from the substrate, (2) hardfacing where a materials more resistant to degradation is applied with good metallurgical bonding and the composition can be close in terms of composition to that of the substrate, (3) build up where a weld deposit is applied to restore the original dimension of the component and the composition of the build layer is exactly similar to that of the substrate and (4) buttering where an intermediate layer is deposited before applying the final coating.The materials used for hardfacing should have melting point close to or lower than the substrate materials. During hardfacing, the temperature of the coating

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“…The alloys are often deposited by arc welding, in which case the cooling rates can be sufficiently large to give nonequilibrium microstructure of M 7 C 3 carbides grow as rods and blades with their long axis parallel to the flow direction in the mold (Dogan & Hawk 1995). The application of these Fe-Cr-C alloys to wear resistant parts exposed to considerable external impact is limited, because they contain large particles of brittle chromium carbides (Lee et al 1996).…”

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Effect of carbide size in hardfacing on abrasive wear

Chotěborský¹,

Hrabě²,

Müller³

et al. 2009

Res. Agric. Eng.

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Abrasive wear of high alloyed overlay materials with high contents of carbide phases of M 7 C 3 depends on the sizes of the carbide particles and on their distribution in an overlay. This work is focused on the study of the carbide particles size effect on abrasive wear. The size of carbide particles of M 7 C 3 type, their distribution (part) in the matrix and their effect on abrasive wear were measured. Hardness in single layers, as well as microhardness of the matrix and of carbide particles, were also measured. The abrasive wear resistance was measured using the pin-on-disk machine with bonded abrasive particles. For the study of the chemical composition, the scanning electron microscopy with energy dispersive X-ray analysis (EDX) was used.Keywords: abrasive wear; weld deposition; hardness; pin-on-disk; carbides 150 RES. AGR. ENG., 55, 2009 (4): 149-158 mercial hardfacing and buffer consumables, in the form of coated electrodes, were used according to the recommendation of the electrode manufacturer. Chemical composition of the electrode is shown in Table 1. Welding conditions for hardfacing depositsThe hardfacing electrodes were deposited on the plate without preheating in the flat position using the manual metal arc welding method. Before welding, the electrodes were dried at 100°C for 2 h. On completion the weld deposits, each test piece was allowed to cool in air. The welding parameters of the electrodes are given in Table 2. Metallography test specimens were then ground using a belt grinder and grit papers and finally polished with Al 2 O 3 powder suspension, cleaned with acetone, and dried. The polished metallography specimens were etched with Vilella-Bains reagent and the microstructures were observed using an optical microscope.The specimens were evaluated using scanning electron microscopy enabling the determination of the chemical composition. Some test specimens were selected to evaluate the worn surfaces by means of scanning electron microscopy, in an attempt to provide a better understanding of the wear mechanism.The overall bulk hardness of the hardfaced layer and microhardness of the matrix and carbide phase were measured using the Vickers hardness tester under 30 kg, respectively 0.1 kg load weight for microhardness. The overlay hardness and the matrix microhardness were measured across the surfacing direction. Chemical analysis was carried out according to Energy dispersive X-ray analysis (EDX) on the side of the specimen in lines of 1 mm length in the direction of surfacing. These lines were placed in distances of every 0.5 mm from the surface to the basic material. size of carbide particlesThe carbide phase geometry and the matrix structure were evaluated using the methods of optical metallography. The phases fraction was determined using the digital image analysis. The carbide phase size was measured according to the carbide surface of the metallographic cut. The form of the carbide cut can be approximated by an ellipse. The surfaces of single carbides A were calculated using the...

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Correlation of microstructure and fracture toughness in high-chromium white iron hardfacing alloys

Cited by 20 publications

References 19 publications

The Relationship between the Microstructure and Abrasive Resistance of a Hardfacing Alloy in the Fe-Cr-C-Nb-V System

The Relationship between the Microstructure and Abrasive Resistance of a Hardfacing Alloy in the Fe-Cr-C-Nb-V System

Hardfacing for Wear, Erosion and Abrasion

Effect of carbide size in hardfacing on abrasive wear

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