Fracture toughness of borides formed on boronized ductile iron

Şen, Uğur; Şen, Şaduman; Köksal, Sakıp; Yılmaz, Feride Taşkın

doi:10.1016/j.matdes.2004.05.015

Cited by 48 publications

(11 citation statements)

References 10 publications

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“…However, the substrates of ductile cast iron alloyed with copper-nickel or copper-nickelmolybdenum also showed the FeB phase, rich in boron (16.3% by weight), orthorhombic crystal structure, elastic modulus of 590 GPa and density of 6.75 g/cm 39, 10,21 . The FeB phase presents a higher hardness but lower toughness, and its formation occurs under tensile stresses (contrary to Fe 2 B formation that occurs under compressive stresses) what commonly give rise to cracks that propagate at its interface [22][23][24][25] . Since boriding is a thermochemical surface treatment the layer thickness is influenced by the temperature and time of treatment, as shown in Figure 5.…”

Section: Resultsmentioning

confidence: 99%

Boro-Austempering Treatment of Ductile Cast Irons

et al. 2018

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Samples of ductile cast irons alloyed with Cu, Cu-Ni and Cu-Ni-Mo were austempered, borided and boro-austempered and characterized for hardness and micro-adhesive wear behavior. The kinetics of layer formation was also studied. The boriding method used was molten borax bath, in periods of 2 and 4 hours at temperatures of 850, 900 and 950 ºC. The direct austempering treatment was performed immediately following the boriding treatment (from 850, 900 and 950 ºC) using molten salt baths at temperatures of 240, 300 and 360 ºC for 4 hours (boro-austempering treatment). For comparative purposes, the conventional austempering treatment was also conducted. Optical microscopy, scanning electron microscopy, Brinell hardness measurements (on the substrate) and Vickers (on the layers) were performed, along with micro-adhesive wear tests. The boriding treatment resulted in the formation of high hardness layers, in the range of 1450 to 1750 HV, with high wear resistance. The wear resistance of borided and boro-austempered samples were increased by 40 times when compared to as cast or austempered samples, indicating the high efficiency of this type of treatment in increasing the wear resistance of this material.

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Section: Resultsmentioning

confidence: 99%

Boro-Austempering Treatment of Ductile Cast Irons

et al. 2018

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“…It increases with boriding time extending and temperatures increasing. The FeB phase was found to be much harder than Fe 2 B phase [8,11], and Ugur Sen also showed [12] that the Vickers microhardness of the FeB phase varied between 1920 and 2140 HV 0.1 , the inner Fe 2 B phase ranged from 1160 to 1920 HV 0.1 in the borides formed on the ductile iron substrate, so the boride layers formed at 950°C show an obvious increase in hardness compared with those at 900°C due to the FeB phase formation. Moreover, as a result of the large load (500 g) applied, borides formed on the HCCIs show an obvious phenomenon of indentation size effect (ISE, which usually involves an apparent decrease in the microhardness with the increasing applied test load) [13].Therefore, both the hardness of the single phase Fe 2 B and the indentation size effect are the dominant reason for the lower surface microhardness of the borides formed at 900°C.…”

Section: Microstructurementioning

confidence: 99%

Effect of boronizing temperature and time on microstructure and abrasion wear resistance of Cr12Mn2V2 high chromium cast iron

Bao-luo

et al. 2008

Surface and Coatings Technology

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“…The wear-resistant phase of the traditional wear-resistant steel mainly includes M 3 C and M 7 C 3 , while the hard phase of the Fe-Cr-B alloy is mainly the M 2 B-type boride [1,2]. When compared with carbides, borides have higher hardness and greater thermal stability [3][4][5][6][7], which is attributed to the significantly low solubility of boron in the Fe matrix. As stated in [8], the solubility of B in α-Fe is only 0.0004% when the temperature is lower than 700 • C. An excessive level of B will cause segregation of the crystal boundary, forming borides (mainly M 2 B) in a network distribution.…”

Section: Introductionmentioning

confidence: 99%

Investigations on Microstructure and Properties of 16 wt% Cr-3 wt% B-0.6 wt% C-1 wt% Mn-Fe Alloy

Ding

Qiu

Ding³

et al. 2018

Metals

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In this paper, a wear-resistant alloy with the chemical composition of 16 wt% Cr-3 wt% B-0.6 wt% C-1 wt% Mn-Fe, in which M 2 B was the antifriction skeleton, was prepared in a medium-frequency induction furnace. The microstructure and mechanical properties were experimentally investigated. The results show that the microstructure of the Fe-Cr-B alloy was composed of lath martensite and clavate, reticular, and clustering borides (M 2 B). After the thermal treatment, the morphology, chemical composition, and volume fraction of the M 2 B did not change significantly. Because of the reduction in element saturation, secondary borides M 23 (B,C) 6 precipitated from the matrix, which resulted in a decrease in matrix microhardness. As a result, the bulk hardness and abrasive resistance of the alloy accordingly decreased, and the impact toughness inversely increased. According to the results of XRD, electronic probe microanalyzer (EPMA), and TEM, the chemical formula of M 2 B was FeCr 0.89 Mn 0.14 (B,C), which resulted in a body-centered tetragonal (BCT) structure. The chemical formula of the M 23 (B,C) 6 was Fe 17.97 Cr 4.13 Mn 1.14 (B,C) 6 , which resulted in a face-centered cubic (FCC) structure.

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Fracture toughness of borides formed on boronized ductile iron

Cited by 48 publications

References 10 publications

Boro-Austempering Treatment of Ductile Cast Irons

Boro-Austempering Treatment of Ductile Cast Irons

Effect of boronizing temperature and time on microstructure and abrasion wear resistance of Cr12Mn2V2 high chromium cast iron

Investigations on Microstructure and Properties of 16 wt% Cr-3 wt% B-0.6 wt% C-1 wt% Mn-Fe Alloy

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