Diffusional Growth Kinetics of Boride Layers at the 13% Cr Steel Interface with Amorphous Boron

Dybkov, V. I.

doi:10.4028/www.scientific.net/ddf.263.183

Cited by 6 publications

(2 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…1). Layer-by-layer X-ray analysis [5,7] and a further comparison of our and literature [8] data showed that with a Fe-10% Cr alloy and the steel the outer layer bordering the boriding agent was the FeB phase, while the inner layer adjacent to the tablet base was the Fe 2 B phase. The structure of boride layers on the surface of Fe-25% Cr alloy samples proved to be more complicated.…”

Section: Resultsmentioning

confidence: 59%

Diffusional Growth Kinetics of Boride Layers on Iron-Chromium Alloys

Dybkov

Goncharuk

Khoruzha

et al. 2008

SSP

Self Cite

View full text Add to dashboard Cite

Two boride layers were found to form at the interface of iiron-chromiium alllloys (10 and 25% Cr) or an industrial 13% Cr steel and boron at 850-950 oC and reaction times in the range 1-12 h. In the case of a Fe-10% Cr alloy and the steel, the layers are based on the FeB and Fe2B compounds. With a Fe-25% Cr alloy, the constituent phases are FeB and CrB for the outer layer and Fe2B and Cr2B for the inner layer. Both layers are characterized by a pronounced texture. Diffusional growth kinetics of boride layers are close to parabolic and can alternatively be described by a system of two non-linear differential equations, producing a good fit to the experimental data. The temperature dependence of the layer growth-rate constants obeys a relation of the Arrhenius type.

show abstract

Section: Resultsmentioning

confidence: 59%

Diffusional Growth Kinetics of Boride Layers on Iron-Chromium Alloys

Dybkov

Goncharuk

Khoruzha

et al. 2008

SSP

Self Cite

View full text Add to dashboard Cite

show abstract

“…Experimental data [38][39][40][41][42][43][44][45][46][47][48][49] on the interaction of five iron-chromium alloys (5-30% Cr) and two industrial steels containing 13 and 25% chromium with boron in a mixture of amorphous boron powder and KBF 4 (activator) in the temperature range of 850-950ºC at reaction times up to 43200 s are juxtaposed and discussed together with findings of other researchers in this work.…”

Section: Introductionmentioning

confidence: 99%

Basics of Formation of Iron Borid e Coatings

Dybkov

2016

J. Miner. Met. Mater. Eng.

View full text Add to dashboard Cite

Main features of formation of iron boride layers in surface coatings on iron, its alloys, notably with chromium, and steels are discussed. Those include their microstructure, phase identity, chemical composition, sequence of occurrence, growth kinetics, and dry wear resistance. Two different kinds of layer microstructure (single-phase and twophase) are shown to exist. Boriding of iron-chromium alloys (5-30% Cr) and chromium steels (13 and 25% Cr) at 850-950ºC and reaction times up to 43200 s is found to result in the formation of a surface coating consisting of two boride layers. In the case of Fe-Cr alloys containing 5-15% chromium and a 13% Cr steel, the outer layer bordering the boriding agent consists of the (Fe,Cr)B compound, while the inner one adjacent to the solid substrate consists of the (Fe,Cr)2B compound. Each boride layer is a homogeneous phase. It is a microstructure of the first type. With Fe-Cr alloys containing 25 and 30% chromium and a 25% Cr steel, each of two boride layers consists of two compounds. The outer layer comprises the (Fe,Cr)B and (Cr,Fe)B compounds, while the inner one comprises the (Fe,Cr)2B and (Cr,Fe)2B compounds. It is a microstructure of the second type that was not observed earlier. With Fe-Cr alloys containing 5% and 10% Cr, boriding during 3600 s leads to the formation of a single (Fe,Cr)2B layer. The (Fe,Cr)B layer occurs after the first-formed (Fe,Cr)2B layer has attained a thickness of more than 100 µm. With other alloys and steels, a reaction time of 3600 s is sufficient for both boride layers (Fe,Cr)B and (Fe,Cr)2B to form. Their distinguishing feature is a {002} texture. Boride layers with the microstructure of the second type exhibit a much higher wear resistance than those with the microstructure of the first type. The difference exceeds an order of magnitude.

show abstract