Production of Electrical Steel by Hot Dipping in Aluminium

2008 ◽  
Vol 273-276 ◽  
pp. 63-68
Author(s):  
Pablo Rodriguez-Calvillo ◽  
P. Bernárdez ◽  
Yvan Houbaert
Keyword(s):  
Steel Substrate ◽  
Low Carbon Steel ◽  
Annealing Treatment ◽  
Processing Route ◽  
Favourable Effect ◽  
Carbon Substrate ◽  
Diffusion Annealing ◽  
Pure Aluminium ◽  
Low Carbon ◽  
Power Losses

The addition of aluminium (and of silicon) to steel increases its electrical resistivity and reduces therefore the power losses in electrical devices. There is also a favourable effect on magnetostriction. Nevertheless, these additions make the steel extremely brittle and very difficult to process through a conventional thermomechanical route. The authors developed an innovative processing route, avoiding the rolling of a brittle steel sheet. The used process consists of the hot dipping of a steel substrate in a pure aluminium bath, followed by a diffusion annealing treatment. In order to study the reaction of the aluminium with the substrates and the diffusion process during further annealing, two substrates (ultra low carbon steel (ULC) and a Fe + 3.4 m.-% Si steel) were used for immersion in a pure aluminium bath. Dipping times and temperatures were varied in the range of 700 to 750 °C and 5 to 1000 sec., respectively. The different surface layers formed during dipping and after annealing were characterised with an Elcometer, by Scanning Electron Microscopy (SEM) and by Energy Dispersive Spectroscopy (EDS). The results show that the chemical composition of the layers obtained is strongly dependant on the initial substrate composition. Diffusion gradients of Al and Si in the steel after hot dipping and diffusion annealing are shown and discussed. Samples with a concentration gradient of Si and Al over the thickness have been produced. There is only a light reduction of the power losses for the substrate with 3.4 m.-% Si. The ultra low carbon substrate presents worse power losses after the processing. Further improvement of the processing is still required.

scholarly journals Effect of Intermetallic Compound Deposits on Wear Resistance and Microhardness on AISI 1020 Steel Substrate Using GTAW Process

2018 ◽  
Vol 221 ◽  
pp. 01003
Author(s):  
J.S. Gill ◽  
Sikandar Singh Dhiman
Keyword(s):  
Wear Resistance ◽  
Oxidation Resistance ◽  
Automobile Industry ◽  
Steel Substrate ◽  
Low Carbon Steel ◽  
Carbon Substrate ◽  
Low Carbon ◽  
Metal Powders ◽  
Gas Tungsten Arc ◽  
Gtaw Process

Enhancing the oxidation resistance along with sufficiently improved mechanical properties of low carbon steel has always been a challenging task for surfacing industry. Modern automobile industry is looking for joining the dissimilar ferrous and non-ferrous metals to reduce the weight of the overall structure and not compromising the strength of the fabrications. This paper deals with the deposition of iron-aluminium intermetallic over a low carbon substrate using gas tungsten arc welding (GTAW) process. Oxidation resistance of the iron and aluminium metal powders deposits in varying ratios and few mechanical and metallurgical properties such as microhardness, microstructure and wear resistance were investigated and are reported in the present paper.

Al-Si-Fe Intermetallics on Fe-Substrates during Hot-Dipping

2010 ◽  
Vol 297-301 ◽  
pp. 1042-1047 ◽  
Author(s):  
Pablo Rodriguez-Calvillo ◽  
Lucia Suarez ◽  
Yvan Houbaert
Keyword(s):  
Growth Kinetics ◽  
Steel Substrate ◽  
Low Carbon Steel ◽  
Bath Temperature ◽  
Core Material ◽  
Diffusion Annealing ◽  
Low Carbon ◽  
Scattered Electron ◽  
Fe Intermetallics ◽  
Kinetics Of

Steels alloyed with Si and Al are used as core material in flux carrying machines, they are commonly called electrical steels, divided into grain oriented and non-oriented when a material without magnetic anisotropy or not is desired and used in transformer and electrical motors, respectively. The appearance of brittle ordered structures when Si+Al content in steel is above 4 m.-% does not always make its industrial production easy. Therefore hot dipping in a Al-Si bath followed by a diffusion annealing was found to be a productive way of steels with high Si and/or Al concentration and to overcome the creation of fragile structures during deformation processes, such as rolling. The formation of different layered Al-(Si)-Fe intermetallics on the steel substrate depends on diverse processing parameters such as bath temperature and composition, immersion time, preheating of the steel substrate and its composition and cooling down to room temperature. This contribution reports the diffusion kinetics of Fe2Al5 products obtained during the hot dipping process in an Al iron saturated and a hypoeutectic Al – 5 m.-% Si baths of ultra low carbon steel and Fe-substrates with 3 m.-% Si, annealed and cold rolled to different thicknesses. The preheating of the samples and bath temperatures were varied between 670 to750°C. Dipping times between 1 to 600 sec. were applied. The different layers and compounds formed were characterized by Scanning Electron Microscopy (SEM), using Back Scattered Electron (BSE) detector and Energy Dispersive Spectroscopy (EDS). The influence of the substrate and bath chemical composition on the growth kinetics of the Fe2Al5 intermetallics was investigated assuming a parabolic law. Si addition retards the growth kinetics and, as result, raises the activation energy from 71.3 to 159.8 kJmol-1, the obtained results are in agreement with the literature.

Effects of Dipping Pretreatment on the Flame Deposition of Carbon Nanostructure on the Low Carbon Steel Substrate

2013 ◽  
Vol 734-737 ◽  
pp. 2269-2272
Author(s):  
Hong Mei Zhu ◽  
Shu Mei Lei ◽  
Tong Chun Kuang
Keyword(s):  
Nitric Acid ◽  
Carbon Steel ◽  
Acid Solution ◽  
Carbon Nanofibers ◽  
Carbon Nanoparticles ◽  
Steel Substrate ◽  
Low Carbon Steel ◽  
Low Carbon ◽  
Carbon Nanostructure ◽  
Flame Method

In this paper, a low carbon steel was used as the substrate to prepare the carbon nanostructural materials by the oxygen-acetylene flame method. The experimental results show that the composite products including nodular carbon nanoparticles and amorphous carbon were obtained on the substrate after a mechanical polishing pretreatment. Comparatively, the short tubular carbon nanofibers with the diameter of around 100 nm were deposited on the substrate pretreated by dipping in the concentrated nitric acid solution. The possible mechanism for the growth of such carbon nanofibers was discussed.

Morphology and Mechanical Properties of a Composite Coating by Electrostatic Dry Spray Method

2021 ◽  
Vol 886 ◽  
pp. 168-174
Author(s):  
Mohanad N. Al-Shroofy ◽  
Hanna A. Al-Kaisy ◽  
Rabab Chalaby
Keyword(s):  
Composite Coating ◽  
Steel Substrate ◽  
Low Carbon Steel ◽  
Spray Coating ◽  
Manufacturing Cost ◽  
Low Carbon ◽  
Spray Method ◽  
Coating Layers ◽  
Al Powder ◽  
Electrostatic Spray

Powder spray coating was used for many applications such as paint decoration and protection against corrosive environments. The electrostatic spray method is used to lower the manufacturing cost and the environmental effect during the production process. It is done by electrostatic device and spray gun to create a layer on the substrate to play a protective role. Different dry powders were mixed to form a composite mixture consisted of Al2O3 and SiC or ZrSiO4 with Al powder as a binder. The powders mixture was deposited by electrostatic spray technique with a high voltage of 15 kV on a low carbon steel substrate of (40 x 10 x 4) mm in dimensions. Two groups of mixtures were used to form the coating layers. Powders of Al2O3 with (20 and 40) weight percent (wt%) of SiC as the first group and (20 and 40) wt% of ZrSiO4 as the second group were used. 5 wt% of Al powder was added as a binder, and the samples were heat treated at 900 C° for 2 hours. A detailed characterization of the composite coating layers was performed using XRD, SEM, and EDX, as well as, micro-hardness measurements. The obtained surface composite layers were smooth and having good particle distribution which leads to enhance roughness values (Ra). Furthermore, the hardness increased with increasing the amount of carbide and zirconia, and the obtained layers show no presence of defects or cracks.

scholarly journals The Microstructure of Annealed Galfan Coating on Steel Substrate

2012 ◽  
Vol 57 (2) ◽  
pp. 517 ◽  
Author(s):  
M. Żelechower ◽  
J. Kliś ◽  
E. Augustyn ◽  
J. Grzonka ◽  
D. Stróż ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Electron Diffraction ◽  
Steel Substrate ◽  
Low Carbon Steel ◽  
Alloy Coating ◽  
Annealed Sample ◽  
Low Carbon ◽  
Interface Area ◽  
Two Phase ◽  
Al Content

The Microstructure of AnnealedGalfanCoating on Steel SubstrateThe commercially availableGalfancoating containing 5-7wt.% of Al deposited on the low carbon steel substrate by hot dipping has been examined with respect to the microstructure of the coating/substrate interface area. The application of several experimental techniques (SEM/EDS, XRD, TEM/AEM/EDS/ED) allowed demonstrating the two-phase structure of the alloy coating in non-treated, commercially availableGalfansamples: Zn-rich pre-eutectoidηphase grains are surrounded by lamellar eutectics ofβ-Al andη-Zn. The transition layer between the alloy coating and steel substrate with the considerably higher Al content (SEM/EDS, TEM/EDS) has been found in both non-treated and annealed samples (600°C/5 minutes). Only the monoclinic FeAl3Znxphase however was revealed in the annealed sample (TEM/electron diffraction) remaining uncertain the presence of the orthorhombic Fe2Al5Znxphase, reported by several authors.

Microstructural and Mechanical Characterizations of Chromium Carbides and Chromium Borides Layers Over Low-Carbon Steel Surface

2020 ◽  
Vol 12 (8) ◽  
pp. 1130-1136
Author(s):  
Rabah Boubaaya ◽  
Omar Allaoui ◽  
Younes Benarioua ◽  
Mokhtar Djendel
Keyword(s):  
Carbon Steel ◽  
Steel Surface ◽  
Solid Medium ◽  
Mechanical Performance ◽  
Low Carbon Steel ◽  
Annealing Treatment ◽  
Hard Coatings ◽  
Low Carbon ◽  
Chromium Carbides ◽  
First Case

Hard coatings based on chromium carbides and chromium borides are widely used in applications that require mechanical performance, i.e., high hardness and low friction coefficient and good corrosion resistance. In this work, we made layers of chromium carbides and chromium borides on the surface of low carbon steel through some specific treatments. For chromium carbides, the cementation in a solid medium followed by electroplating of chromium on the surface and finally the application of annealing treatment at temperatures between 500 and 1100 °C for 1 hour. For chromium borides, the boriding treatment in solid medium at 900 °C for 4 hours followed by chromium electroplating on the steel surface and finally the application of annealing treatment at temperatures at 950 °C for 1 and 2 hours. The obtained results show that, in the first case, the cemented layer and the chromium deposited on the surface combine to form chromium carbides on the treated surface after annealing. Similarly, for the second case, boron diffusion and chromium deposition lead to chromium borides on the treated surface. The characteristics of the chromium carbides and chromium borides obtained are very similar to those of chromium carbides and chromium borides obtained by other processes.

Preparation and characterization of pulsed electrodeposited cobalt–graphene nanocomposite coatings

2019 ◽  
Vol 233 (12) ◽  
pp. 2469-2477 ◽  
Author(s):  
R Raveen ◽  
J Yoganandh ◽  
S SathieshKumar ◽  
N Neelakandeswari
Keyword(s):  
Steel Substrate ◽  
Research Work ◽  
Low Carbon Steel ◽  
Trisodium Citrate ◽  
Nanocomposite Coating ◽  
Industrial Applications ◽  
Nanocomposite Coatings ◽  
Low Carbon ◽  
Mechanical And Tribological Properties ◽  
Graphene Nanocomposite

Cobalt–graphene nanocomposite coatings possess unique mechanical and tribological properties which attract researchers to explore its potential for various industrial applications. This research work presents the investigation on cobalt–graphene nanocomposite coatings, with two different graphene compositions cobalt–graphene (0.15 and 0.45 wt%) prepared by pulsed electrodeposition from aqueous bath involving cobalt chloride, trisodium citrate, and citric acid on low carbon steel substrate. Studies on coating morphology, microhardness, tribological characteristics such as wear and corrosion for the cobalt–graphene nanocomposite coatings were reported. Cobalt–graphene (0.45 wt%) nanocomposite coating which exhibits low wear rate in all load conditions due to the self-lubricating property of graphene and cobalt–graphene (0.15 wt%) nanocomposite coating shows higher corrosion resistance due to its layered cauliflower surface morphology.

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