Formation of Structure of an Annealed High-Speed Steel upon Laser Surface Melting

Чаус, А. С.; Maksimenko, Aleksandr V.; Fedosenko, N. N.; Čaplovič, Ľubomír; Мышковец, В. Н.

doi:10.1134/s0031918x19040033

Cited by 3 publications

(4 citation statements)

References 28 publications

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“…Figure 4e shows the microstructure of the heat-affected zone where two characteristic areas could be distinguished. By observing this zone in contrast of reflected electrons, it is possible to identify both brighter regions, most likely containing alloy austenite, as also described in [40], as well as darker regions consisting of finer martensite needles with carbides originating from a steel substrate.…”

Section: Resultsmentioning

confidence: 87%

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

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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.

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Section: Resultsmentioning

confidence: 87%

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

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“…The mass loss of the untreated and LSMed samples in deionised water is 35 ± 1 and 14 ± 0.3 mg, whereas the mass loss in 3.5 wt% NaCl solution is 40 ± 0.6 and 20 ± 0.3 mg after 8-h CE, respectively. The mean depth of erosion ( MDE ) and the mean depth of erosion rate ( MDER ) can be used to evaluate CE resistance and calculated as follows: 3–57 where Δw is the mass loss (mg), ρ is the density of the materials (g/cm 3 ), s is the eroded area (1 cm 2 in this study), Δ T is the interval time (h), MDE in μm and MDER in μm/h. The CE resistance R e (h μm −1 ) is the reciprocal of MDER.…”

Section: Resultsmentioning

confidence: 99%

“…In general, the grain size of untreated sample is about 10.4 μm and that of LSMed sample is only 1.04 μm, indicating that the LSM can significantly refine the grain size due to the rapid melting and solidification rate. Chaus et al 37 also found that LSM has fast cooling characteristics, thus it will result in a higher crystallisation rate and subsequently grain refinement. Cui et al 38 reported that there is a strong convection in the molten pool of LSM known as Marangoni convection, which will squeeze the columnar grains and break them, and a large number of columnar grain fragments will be evenly distributed in the molten pool as the crystal nucleus.…”

Section: Phase Constituents and Microstructurementioning

confidence: 99%

Iso-material manufacturing of 304 stainless steel: Microstructure, corrosion-cavitation erosion synergistic behaviour

Cao,

Wu,

Wang

et al. 2024

Materials Science and Technology

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Different from additive or subtractive manufacturing, iso-material manufacturing (also named isovolumetric manufacturing) was proposed in this work by laser surface melting (LSM), aiming at enhancing resistance to corrosion and cavitation erosion (CE) of 304 stainless steel. Experimental results showed that partial austenite transformed into martensite after LSM. The corrosion resistance of LSMed sample was improved. LSMed sample exhibited enhanced CE resistance, and was 2.5 and 2 times that of untreated sample in deionised water and 3.5 wt% NaCl solution, respectively. The passivation film for LSMed sample exhibited a high re-passive and self-repairing ability of passivation film. LSMed sample in this study exhibits a high or comparable corrosion and CE resistance in comparison with samples prepared by other fabrication method reported previously.

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“…It is well-known that tensile stresses developed during laser treatment can initiate cracks in the cross-section of the LMZ. When the plasticity of the material is too low to provide stress relaxation, cracks can propagate through the entire LMZ into the bonding zone [44,45] and even into the substrate [46]. In this context, it is important to note that no cracks were detected in the LMZ in all studied samples.…”

Section: Microstructure Characterization Of the Samples That Were All...mentioning

confidence: 88%

The Effect of Varying Parameters of Laser Surface Alloying Post-Treatment on the Microstructure and Hardness of Additively Manufactured 17-4PH Stainless Steel

Chaus,

Devoino,

Sahul

et al. 2024

Crystals

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In the present work, the evolution of the microstructure in additively manufactured 17-4PH stainless steel, which was subjected to laser surface alloying with amorphous boron and nitrogen at the varying process parameters, was studied. The main aim was to improve surface hardness and hence potential wear resistance of the steel. Scanning electron microscopy, wavelength-dispersive X-ray spectroscopy (WDS), and Auger electron spectroscopy (AES) were used. It was shown that the final microstructure developed in the laser-melted zone (LMZ) is dependent on a variety of processing parameters (1 and 1.5 mm laser beam spot diameters; 200, 400, and 600 mm/min laser scan speeds), which primarily influence the morphology and orientation of the eutectic dendrites in the LMZ. It was metallographically proven that a fully eutectic microstructure, except for one sample containing 60 ± 4.2% of the eutectic, was revealed in the LMZ in the studied samples. The results of WDS and AES also confirmed alloying the LMZ with nitrogen. The formation of the boron eutectic and the supersaturation of the α-iron solid solution with boron and nitrogen (as a part of the eutectic mixture) led to enhanced microhardness, which was significantly higher compared with that of the heat-treated substrate (545.8 ± 12.59–804.7 ± 19.4 vs. 276.8 ± 10.1–312.7 ± 11.7 HV0.1).

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Formation of Structure of an Annealed High-Speed Steel upon Laser Surface Melting

Cited by 3 publications

References 28 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

Iso-material manufacturing of 304 stainless steel: Microstructure, corrosion-cavitation erosion synergistic behaviour

The Effect of Varying Parameters of Laser Surface Alloying Post-Treatment on the Microstructure and Hardness of Additively Manufactured 17-4PH Stainless Steel

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