Boronizing and borochromizing in a vibrofluidized bed

Грачев, С. В.; Mal’tseva, L. A.; Maltseva, T. V.; Kolpakov, A. S.; Dmitriev, M. Yu.

doi:10.1007/bf02471210

Cited by 7 publications

(3 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Information can be found in the literature on the use of processes involving simultaneous introduction of boron and additional chemical elements. These can be, for example, carbon [9], copper [10], aluminium [11], or chromium [10,[12][13][14][15][16]. The application of the process consisting of diffusive saturation with boron and chromium contributes to reduction of brittleness; the produced layer thus has a hardness similar to the boronized layer.…”

Section: Introductionmentioning

confidence: 99%

Microstructural and Mechanical Properties of B-Cr Coatings Formed on 145Cr6 Tool Steel by Laser Remelting of Diffusion Borochromized Layer Using Diode Laser

et al. 2021

View full text Add to dashboard Cite

The paper presents study results focused on the microstructural, mechanical, and physicochemical properties of B-Cr coatings obtained by means of modification of diffusion borochromized layers by diode laser beam. The studies were conducted on 145Cr6 tool steel. Diffusion borochromized layers were produced at 950 °C in powder mixture containing boron carbides as a source of boron and ferrochrome as a source of chromium. In the next step these layers were remelted using laser beam. Powers: 600, 900, and 1200 W were used during these processes. The microstructure, microhardness, chemical composition, as well as wear and corrosion resistance of newly-formed B-Cr coatings were determined. As a result of laser beam interaction, the diffusion borochromized layer was mixed with the steel substrate. The study showed that too low laser beam power causes cracks in the newly formed B-Cr coating, and on the other hand, too higher laser beam power causes deep remelting resulting in the loss of microhardness. The reduced corrosion resistance in comparison with diffusion borochromized layers was caused by occurrence cracks or deep remelting. For B-Cr coatings produced using laser beam power 600 W, a small decrease in wear resistance was observed, but note that this coating was much thicker than diffusion borochromized layers. On the other hand, laser beam power of 1200 W caused a significant decrease in wear resistance. Newly formed B-Cr coatings had an advantageous microhardness gradient between the layer and the substrate.

show abstract

Section: Introductionmentioning

confidence: 99%

Microstructural and Mechanical Properties of B-Cr Coatings Formed on 145Cr6 Tool Steel by Laser Remelting of Diffusion Borochromized Layer Using Diode Laser

et al. 2021

View full text Add to dashboard Cite

show abstract

“…The investigation of the borochromizing process as an optimized version of boronizing is an open field of research. In particular, experimental studies on chromizing a boronized steel (boronizing + chromizing) [6][7][8], boronizing a chromized steel (chromizing + boronizing) [9,10] and the simultaneous borochromizing [11][12][13] are referred in the literature. In some of these cases, the examined property of the borochromized materials was resistance against friction [6,10] and the corrosion resistance [12].…”

Section: Introductionmentioning

confidence: 99%

The influence of chromium as a diffusive additive in the boronizing treatment of AISI 4140 steel on the corrosion resistance of the coating evaluated by Electrochemical Impedance Spectroscopy (EIS)

et al. 2020

View full text Add to dashboard Cite

A large variety of protective coating is being used in industrial applications to improve the resistance of the metallic substrates against corrosion. The pack-cementation method for boronizing and borochromizing is effective to produce extremely hard and corrosion resistant thick coatings and, additionally, is a low-cost and simple technique. In the present study, AISI 4140 steel specimens underwent boronizing and afterwards chromizing by the pack-cementation method using B4C as boron source and Fe-Cr as chromium source, respectively. In both treatments the appropriate activators were used. After chromizing the boronized substrate, a mixed boride phase FeCrB was formed, as it was confirmed by X-ray Diffractometry (XRD). The boronized and the borochromized specimens were subjected to Electrochemical Impedance Spectroscopy (EIS). From the analysis of the frequency response of the coating systems (Bode and Nyquist display), the conclusion that the borochromized specimens were significantly more corrosion resistant was extracted. Finally, data of optical and electron microscopy contribute to the validity of the conclusions.

show abstract

“…Borochromizing is a type of TCT, where mainly steel products are simultaneously saturated with boron and chromium in order to improve the characteristics of boride wear-resistant layers, i.e. increasing their heat and corrosion resistance, as well as reducing brittleness [4][5][6][7]. Boroaluminizing method is used for the same purposes.…”

Section: Introductionmentioning

confidence: 99%

Fe-Me-B Diffusion Layers for Surface Modification of Carbon Steels

Mishigdorzhiyn

Samaev

Мосоров

et al. 2020

DDF

View full text Add to dashboard Cite

Multicomponent boron-based diffusion layers are capable to provide a wider variety of surface improvements compared to pure boriding. In this research, we consider a way to increase mechanical properties of carbon steels by using two-component thermal-chemical treatment (TCT) such as boroaluminizing (B+Al), and boronickelizing (B+Ni). Diffusion treatment of steel surface was carried out by pack method in powder mixtures, and pastes, containing the above-mentioned elements and sodium fluoride as an activator. The exposure time was 3 hours, the treatment temperature was 950 °C. Pure boriding was conducted additionally to compare with two-component methods. The metallographic analysis revealed diffusion layers with a tooth-like structure after boriding and B+Ni. Typical composition of boride layer with iron boride FeB as an outer phase and Fe2B as an inner one was obtained after the first method. EDS analysis revealed a small amount of Ni (less than 1%) in boronickelized layer. Although XRD analysis revealed Ni2B, Fe3Ni3B besides iron borides and carboborides after B+Ni. Another structure was obtained after B+Al – namely a layered microstructure with outer softer iron aluminides and iron borides beneath. The thickest layer was obtained after boriding with the thickness of 140-160 μm, where higher value corresponds to low-carbon steel and vice versa. While for boroaluminizing the layer thickness was around 120-140 μm and for boronickelizing - 60-100 μm. Microhardness profiles differ significantly depending on the TCT method. For instance, initial high values followed by a drastic drop of hardness for boriding and boronickelizing. Wave type profiles characterize the microhardness distribution on boroaluminized samples. Wear tests indicated that samples with boride layer were the most wear resistant and the least resistant were the samples after B+Al. Fe-Me-B layers with the tooth-like structure are superior to the ones with the layered structure.

show abstract

Boronizing and borochromizing in a vibrofluidized bed

Cited by 7 publications

References 0 publications

Microstructural and Mechanical Properties of B-Cr Coatings Formed on 145Cr6 Tool Steel by Laser Remelting of Diffusion Borochromized Layer Using Diode Laser

Microstructural and Mechanical Properties of B-Cr Coatings Formed on 145Cr6 Tool Steel by Laser Remelting of Diffusion Borochromized Layer Using Diode Laser

The influence of chromium as a diffusive additive in the boronizing treatment of AISI 4140 steel on the corrosion resistance of the coating evaluated by Electrochemical Impedance Spectroscopy (EIS)

Fe-Me-B Diffusion Layers for Surface Modification of Carbon Steels

Contact Info

Product

Resources

About