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 ◽  
...  

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.

2019 ◽  
Vol 813 ◽  
pp. 159-164
Author(s):  
Carlos Alberto Souto ◽  
Gustavo Faria Melo da Silva ◽  
Laura Angelica Ardila Rodriguez ◽  
Aline C. de Oliveira ◽  
Kátia Regina Cardoso

Coatings with high entropy alloys of the AlCoCrFeNiV system were obtained by selective laser melting on low carbon steel substrates. The effect of the variation of the Fe and V contents as well as the laser processing parameters in the development of the coating were evaluated. The coatings were obtained from the simple powder mixtures of the high purity elemental components in a planetary ball mill. The coatings were obtained by using CO2 laser with a power of 100 W, diameter of 0.16 mm, and scan speed varying from 3 to 12 mm/s. Phase constituents, microstructure and hardness were investigated by XRD, SEM, and microhardness tester, respectively. Wear resistance measurements were carried out by the micro-abrasion method using ball-cratering tests. The coatings presented good adhesion to the substrate and high hardness, of the order of 480 to 650 HV. Most homogeneous coating with nominal composition was obtained by using the higher scan speed, 12 mm/s. Vanadium addition increased hardness and gave rise to a high entropy alloy coating composed by BCC solid solutions. Ball cratering tests conducted on HEA layer showing improvement of material wear resistance, when compared to base substrate, decreasing up to 88% its wear rate, from 1.91x10-6 mm3/Nmm to 0.23x10-6 mm3/Nmm.


2013 ◽  
Vol 734-737 ◽  
pp. 2269-2272
Author(s):  
Hong Mei Zhu ◽  
Shu Mei Lei ◽  
Tong Chun Kuang

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.


2020 ◽  
Vol 1012 ◽  
pp. 401-406
Author(s):  
Carlos Trivellato de Carvalho Filho ◽  
Pedro Paiva Brito

In the present work, the friction surfacing process was applied to manufacture aluminum alloy (AA6351) coatings on low carbon steel (AISI 1020) substrates. After friction surfacing the AA6351 deposited coatings were submitted to two finishing process in order to adjust surface roughness: milling and milling followed by sanding. The corrosion behavior of the two finishing process was compared with the as-deposited condition in order to determine the influence of surface roughness on the corrosion resistance of friction surfacing coatings. The corrosion behavior was examined by electrochemical impedance spectroscopy and potentiodynamic polarization in a 3.5wt.%NaCl solution containing naturally dissolved O2. The results obtained indicated that the elevated surface roughness observed in the as-deposited condition led to relatively lower corrosion resistance in comparison, with lower values for polarization resistance and more anodic corrosion potential.


1997 ◽  
Vol 37 (5) ◽  
pp. 512-518 ◽  
Author(s):  
Hiroyuki Ohtsubo ◽  
Hideki Sogo ◽  
Kiyomichi Nakai ◽  
Yasuya Ohmori

2012 ◽  
Vol 572 ◽  
pp. 249-254 ◽  
Author(s):  
Xiang Long Yu ◽  
Zheng Yi Jiang ◽  
Dai Jun Yang ◽  
Dong Bin Wei ◽  
Quan Yang

Precipitation behavior of magnetite particles in the thermal grown oxide scale during isothermal cooling of microalloyed low carbon steel was studied using scanning electron microscopy (SEM) and thin film X-ray. The oxide scale was generated from Gleeble 3500 Thermal Mechanical Simulator connected with a humid air generator, to simulate 550 and 450C isothermal treatments. Several types of magnetite precipitates were observed during different cooling processes with respect to the possible mechanisms of precipitation have been discussed. It is found that magnetite particles is as a result of pro-eutectoid precipitation from oxygen-rich wustite, and also as a product of the partial decomposition of wustite during the cooling process due to change of oxygen concentration and migration of iron ions. Furthermore, microalloyed elements in steel reduce the stability of wustite thereby facilitate the precipitation process, whose products of multi-phase oxide finally determine the adhesive strength of oxide scale and steel substrate.


2021 ◽  
Vol 39 (7) ◽  
pp. 1052-1059
Author(s):  
Mohammed J. Kadhim ◽  
Mahdi M. Hanon ◽  
Suhair A. Hussain

In this article a 1.8kW continuous wave of high power CO2 laser was used to clad of a titular composition of Ni – 10 wt% Al powder on cold rolled 0.2% carbon steel substrate. The feed rate was kept constant after many preliminary claddings at approximately 11 g/min.  In order to produce clads with different specific energies and interaction times, different traverse speeds were used in the range of 1.5 to 12.5 mm/s. The microstructure of substrate was changed at the heat affected zones under the variety of specific energies. The cladded coatings showed the presence of ɣ solid solution and β (NiAlFe) phases. A strong metallurgical bonding produced between the substrate and the clad coat at fluence higher than 48 J/mm2. The changing in microstructure were observed using both microscope and SEM. The microhardness was evaluated using Vickerʼs microhardness test. The microstructure of the substrate was ferrite and pearlite transformed to martensite at the region adjacent to the clad interface. It followed by a three regions can be classified, a grain growth zone (large grains of austenite/ferrite and pearlite), recrystallization zone (fine grains of austenite/ferrite and pearlite) and recovery zone (the structure has a little changes from the structure of low carbon steel). The microhardness testing result showed higher values for the clad regions compared with substrate. This study emphasize the possibility to develop a temporary new graded material.


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