Electron-Beam Cladding of Boron Carbide on Low-Alloyed Steel at the Air Atmosphere

2014 ◽  
Vol 698 ◽  
pp. 369-373 ◽  
Author(s):  
Dina S. Krivezhenko ◽  
I.S. Laptev ◽  
T.A. Zimoglyadova

An investigation of coatings obtained by cladding of boron carbide on a low-alloyed steel substrate by an electron beam injected into the air atmosphere was carried out. It was shown that hardened layers had a heterogeneous structure formed during rapid cooling. It was established that a volume fraction of iron borides in the surface layer had a considerable impact on mechanical properties of the material studied.

Author(s):  
Hongcai Wang ◽  
Lijie Cao ◽  
Yujiao Li ◽  
Mike Schneider ◽  
Eric Detemple ◽  
...  

AbstractHeavy plate steels with bainitic microstructures are widely used in industry due to their good combination of strength and toughness. However, obtaining optimal mechanical properties is often challenging due to the complex bainitic microstructures and multiple phase constitutions caused by different cooling rates through the plate thickness. Here, both conventional and advanced microstructural characterization techniques which bridge the meso- and atomic-scales were applied to investigate how microstructure/mechanical property-relationships of a low-carbon low-alloyed steel are affected by phase transformations during continuous cooling. Mechanical tests show that the yield strength increases monotonically when cooling rates increase up to 90 K/s. The present study shows that this is associated with a decrease in the volume fraction of polygonal ferrite (PF) and a refinement of the substructure of degenerated upper bainite (DUB). The fine DUB substructures feature C-rich retained austenite/martensite-austenite (RA/M-A) constitutes which decorate the elongated micrograin boundaries in ferrite. A further increase in strength is observed when needle-shaped cementite precipitates form during water quenching within elongated micrograins. Pure martensite islands on the elongated micrograin boundaries lead to a decreased ductility. The implications for thick section plate processing are discussed based on the findings of the present work.


2014 ◽  
Vol 1040 ◽  
pp. 778-783 ◽  
Author(s):  
Daria Mul ◽  
Dina S. Krivezhenko ◽  
Daria B. Lazurenko ◽  
Olga G. Lenivtseva ◽  
Alexandra Chevakinskaya

The surface layer of steel was reinforced by electron-beam cladding at air atmosphere. Two types of powder mixtures were used to receive coatings: (1) titanium and graphite, (2) titanium and boron carbide. The formation of heterogeneous structure was observed in specimens after the electron-beam treatment by the methods of optical microscopy and scanning electron microscopy. The X-ray diffraction analysis was used to analyze the phase composition of the coatings. The wear resistance level of the coatings was estimated by friction test against loosely fixed abrasive particles. It was found that surface alloying of steel with carbon containing components led to the formation of material with an enhanced wear resistance level.


Author(s):  
K. Bobzin ◽  
W. Wietheger ◽  
J. Hebing ◽  
L. Gerdt ◽  
H. Krappitz ◽  
...  

Abstract Ni-based brazing coatings with tungsten or chromium carbides are used for wear and corrosion protection in various applications. Steam turbine blades especially present a highly stressed application in which in particular the resistance to erosion and corrosion is essential. Therefore, novel tape architectures of brazed coatings have been developed and investigated within this study. In contrast to the use of powders, the application by means of tapes offers a high potential with regard to later use in industry due to the reproducible handling and automation. In this work, different coating systems were successfully deposited by means of vacuum brazing on X12CrNiMo-12 steel substrate. In order to achieve a sufficient fracture toughness of the coatings, pure nickel powder was added to the tapes. The influence of this additive on the mechanical properties was analyzed by means of three-point bending tests. A positive effect has been observed when adding a volume fraction of φ(Ni) = 25% of nickel, increasing the flexural strength up to σf = 580 MPa. Furthermore, the surface hardness of the coating has been analyzed depending on coating architecture and post-deposition treatment by grinding.


Author(s):  
M. Yu. Matrosov ◽  
P. G. Martynov ◽  
A. V. Mitrofanov ◽  
K. Yu. Barabash ◽  
T. V. Goroshko ◽  
...  

High-strength sheet product of low-alloyed steel, used at manufacturing of heavy-loaded structures, must have, apart from wear resistance, high toughness, good weldability, ability to hot and cold forming, machinability and low cost. Combination of these properties based on forming fine grain austenite structure before the martensitic transformation at definite its thermal treatment modes. Results of study of microstructure, fine structure and mechanical properties of high-strength boron-containing low-alloyed steel after different technological methods of the rolled product manufacturing presented: high-temperature hot rolling and twostages controlled rolling with accelerated cooling followed by thermal treatment – quenching with tempering. Variants of optimal modes of thermal treatment determined, providing combination of high level of impact toughness under negative temperatures, hardness and strength properties of sheet product. The two considered in the article technological variants, comprising treatment of low-alloyed steel with boron (hot rolling and two-stages controlled rolling with accelerated cooling) followed by thermal treatment results in forming fine structure of tempered martensite, which provides high mechanical properties, meeting the made requirements. Depending on the heating temperature before quenching in the range 770–950 °С, the morphology of the actual steel grain is changing from elongated to equiaxed, which is connected with the metal recrystallization process during heating after plastic deformation. The study results obtained allow to optimize the thermal treatment processes of sheet product of low-alloyed boron containing steel for particular conditions of application.


2015 ◽  
Vol 813-814 ◽  
pp. 116-120
Author(s):  
K.S. Arun ◽  
T. Panneerselvam ◽  
S. Raghuraman

Now a day’s Hybrid Metal Matrix composites has a large number of applications in automobiles, aircrafts and structural applications like brake rotors, engine parts and cylinder liners. The aim of this study is to determine the mechanical properties of boron carbide (B4C) and zirconium silicate (ZrSiO4) particulate reinforced with AA6063 alloy composites. In this experimental study, B4C and ZrSiO4 particulates reinforced with AA6063 composites were manufactured by stir casting technique. Mechanical properties of these composite materials were investigated by different weight percentages, 3%, 6%, 9% of boron carbide (B4C) and 9%, 6%, 3% of zirconium silicate (ZrSiO4) respectively. The mechanical properties evaluation reveals variations in hardness and the tensile strength values with the composite combinations investigated in this work. From the experimental studies, the optimum volume fraction of hybrid reinforcement in AA6063 alloy on the basis of mechanical properties and SEM analysis is also determined.


Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6948
Author(s):  
Andrey Filippov ◽  
Nikolay Shamarin ◽  
Evgeny Moskvichev ◽  
Nikolai Savchenko ◽  
Evgeny Kolubaev ◽  
...  

Electron beam additive wire-feed deposition of Cu-7.5wt.%Al bronze on a stainless-steel substrate has been carried out at heat input levels 0.21, 0.255, and 0.3 kJ/mm. The microstructures formed at 0.21 kJ/mm were characterized by the presence of both zigzagged columnar and small equiaxed grains with 10% of Σ3 annealing twin grain boundaries. No equiaxed grains were found in samples obtained at 0.255 and 0.3 kJ/mm. The zigzagged columnar ones were only retained in samples obtained at 0.255 kJ/mm. The fraction of Σ3 boundaries reduced at higher heat input values to 7 and 4%, respectively. The maximum tensile strength was achieved on samples obtained with 0.21 kJ/mm as tested with a tensile axis perpendicular to the deposited wall’s height. More than 100% elongation-to-fracture was achieved when testing the samples obtained at 0.3 kJ/mm (as tested with a tensile axis coinciding with the wall’s height).


2015 ◽  
Vol 1128 ◽  
pp. 332-337
Author(s):  
Constantin Paulin ◽  
Daniela Lucia Chicet ◽  
Bogdan Istrate ◽  
Petru Avram ◽  
Corneliu Munteanu

TThe present study is an attempt to observe and evaluate the dry rolling wear behavior [1] of three types of Ni-base coatings on an Amsler type wear machine, against low-alloyed steel discs. The tested coatings were obtained by flame spraying (on the same low-alloyed steel substrate as the discs) using commercial Ni-base self-fluxing powders: 1060-00 and 1355-20 type (manufactured by Hoganas) and JK 586 type (manufactured by Deloro Stelite Co). In order to increase the strength of the layers, the deposition was followed by fusing [2]. The tests were conducted on pairs of coated – uncoated discs at the same load and the same speed in all three cases. In order to evaluate the wear behavior, there were observed and measured the surface roughness and the rolling path profiles. A severe wear regime with adhesion as the main phenomenon was observed in case of the low-alloyed steel discs.


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