On the defects of enamel coatings

2019 ◽  
pp. 145-150
Author(s):  
T. O. Soshina ◽  
V. R. Mukhamadyarovа
Keyword(s):  
Heat Treatment ◽  
Surface Tension ◽  
Electron Microscope ◽  
Enamel Coating ◽  
Surface Defects ◽  
Linear Expansion ◽  
Corrosion Properties ◽  
Treatment Conditions ◽  
Mechanical And Corrosion Properties ◽  
Coefficient Of Linear Expansion

The defects destroy the integrity of the enamel, and the paper examines the influence of the physical-mechanical and corrosion properties of frits and heat treatment on the defectiveness of the enamel coating. The surface defects were scanned by electron microscope. It has been established that the defectiveness of enamel coatings depends on the melting index, temperature coefficient of linear expansion, surface tension of the frits, and heat treatment conditions. When burning rate of the enamel coating decreases, the fine-meshed structure of the enamel changes, and the size of the defects decreases.

The structure and properties of sheets from the new alloy V-1381 of the Al – Mg – Si system

2021 ◽  
Vol 5 ◽  
pp. 18-27
Author(s):  
A. A. Selivanov ◽  
◽  
K. V. Antipov ◽  
Yu. S. Oglodkova ◽  
A. S. Rudchenko ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Arc Welding ◽  
Structure And Properties ◽  
Strengthening Phase ◽  
Critical Rate ◽  
Corrosion Properties ◽  
Β Phase ◽  
Mechanical And Corrosion Properties ◽  
20 Nm ◽  
6Xxx Series

The results of the development of a new alloy of the Al – Mg – Si system of the 6xxx series, which received the V-1381 grade, are presented. The influence of the composition and modes of heat treatment on the mechanical and corrosion properties of sheets with a thickness of 1,0 and 3,0 mm, manufactured under the conditions of FSUE “VIAM”, was investigated. Average level of sheet properties: UTS = 410 MPa, YTS = 360 MPa, El = 11.5 %; fatigue crack growth (dl/dN) = 0,59 mm/kcycle at ΔK = 18,6 MPa·m1/2, intergranular corrosion ≤ 0,15 mm, exfoliation corrosion 4 points. It was found that the structure of the sheets is recrystallized, the main strengthening phase is the coherent matrix β’(Mg2Si)-phase evenly distributed in the volume of grains with a high density. There is also a heterogeneous origin of β′-phase on dislocations and dispersoids. At grain boundaries there are zones free from emissions with a width of 15 – 20 nm. Dispersoids of various morphologies are observed in the tested samples. Temperature and heat values of phase transformations in ingots and sheets are determined and established liquidus and solidus points. The sheet weldability was evaluated by automatic argon-arc welding and the critical rate of deformation of the weld metal during crystallization was determined, at which no cracks were formed in it. Laser welding mode has been developed to ensure optimal formation of geometric parameters of the weld.

A Free-Lead and Cadmium of Antimony Ruby Glass Composition and its Preparation Method

2012 ◽  
Vol 535-537 ◽  
pp. 2158-2161
Author(s):  
Hua Juan Tang
Keyword(s):  
Heat Treatment ◽  
Preparation Method ◽  
Glass Composition ◽  
Linear Expansion ◽  
Soda Lime ◽  
Matrix Composition ◽  
Ruby Glass ◽  
Lead And Cadmium ◽  
Coefficient Of Linear Expansion

The antimony ruby glass is prepared by soda-lime silica system as matrix composition which coefficient of linear expansion is appropriate for the ordinary glassware.UV-VIS spectrometer is used to measure the transmittance curves of various amount Sb2O3 glasses Relation between amount Sb2O3 and transmittance of antimony glasses are investigated which indicates that the tSuperscript textransmittance of antimony glass becomes lower with Sb2O3 amount increasing. Comparing un-treatment with heat treatment antimony glass, the dominate wavelength moves toward the red wavelength and the pure color increases.

scholarly journals Investigation of the thermal properties of mullite-cordierite materials

2018 ◽  
Vol 118 ◽  
pp. 111-118
Author(s):  
О. V. Savvova ◽  
O. I. Fesenko ◽  
V. D. Timofeеv ◽  
Ya. V. Poviderna
Keyword(s):  
Heat Treatment ◽  
Thermal Properties ◽  
Fire Resistance ◽  
Glass Ceramic ◽  
Linear Expansion ◽  
High Strength ◽  
Ceramic Materials ◽  
Glass Ceramic Materials ◽  
Cordierite Glass ◽  
Coefficient Of Linear Expansion

Based on the analysis of existing mullite-cordierite sitalls, the need to create high-strength materials of this type for individual and local protection against high-speed loads has been determined. They should be characterized by lower cost, due to low-temperature short-term heat treatment using domestic raw materials. An important aspect of ensuring the effective protective effect of an armor-element, in addition to its armor resistance and survivability, is the ability to withstand the effects of open flame and combustible mixtures, which is determined by the thermal properties of the sitalls. The aim of this work is to study the thermal properties, namely thermal expansion coefficient and fire resistance, high strength mullite-cordierite glass-ceramics that they are developed by us earlier. The temperature coefficient of linear expansion was determined using a quartz vertical dilatometer QVD-5A (ASTM C 372-94 (2007)), fire resistance according to GOST 33000—2014. According to X-ray diffraction and differential thermal analyzes, the experimental samples were divided into two groups according to the formation mechanism of structure and phase composition of glass materials during heat treatment. For each of the materials groups, the influence of the chemical and phase compositions on the thermal coefficient of linear expansion of the original mullite-cordierite glass materials and glass-ceramic materials (sitalls) thermally treated using two-stage heat treatment was determined. The study of the fire resistance of the developed glass-ceramic materials made it possible to establish that they withstand the thermal load in a certain mode for 360 minutes. It has been established that providing high thermal- and fire resistance (RE 360 (h)) is a determining factor in the production of hardened glass crystalline materials that are able to resist to thermal destroying at sharp temperature change.

scholarly journals Performance Evaluation of the Effects of Post Weld Heat Treatment on the Microstructure, Mechanical and Corrosion Potentials of Low Carbon Steel

2019 ◽  
Vol 44 (1) ◽  
pp. 41-47 ◽  
Author(s):  
Isiaka Oluwole Oladele ◽  
Davies Babatunde Alonge ◽  
Timothy Olakunle Betiku ◽  
Emmanuel Ohiomomo Igbafen ◽  
Benjamin Omotayo Adewuyi
Keyword(s):  
Heat Treatment ◽  
Carbon Steel ◽  
Low Carbon Steel ◽  
Welding Process ◽  
Post Weld Heat Treatment ◽  
Welding Parameters ◽  
Low Carbon ◽  
Corrosion Properties ◽  
Mechanical And Corrosion Properties ◽  
Weld Heat

The effect of Post Weld Heat Treatment (PWHT) on the microstructure, mechanical and corrosion properties of low carbon steel have been investigated. The welding process was conducted on butt joint using Manual Metal Arc Welding (MMAW) techniques at a welding voltage of 23 V and welding current of 110 A with the use of E6013 and 3.2 mm diameter as filler material. Heat treatment through full annealing was carried out on the welded low carbon steel. The mechanical properties (hardness, impact toughness and tensile properties) of the AW and PWHT samples were determined. The microstructure of the AW and PWHT samples was characterized by means of an optical microscopy. Corrosion behavior of the sample was studied in3.5 wt.% NaCl environment using potentiodynamic polarization method. The results showed that the AW samples has good combination of mechanical and corrosion properties. The microstructure revealed fine grains of pearlite randomly dispersed in the ferrite for the AW base metal (BM) sample while agglomerated and fine particle of epsilon carbide or cementite randomly dispersed on the ferritic phase of the heat affected zone (HAZ) and weld metal (WM), of the AW, respectively. The PWHT samples shows that the annealing process allow diffusion and growth of the fine grains into partial coarse grains of ferrite and pearlite which did not encourage improvement of the properties. Therefore, it was concluded that the welding parameters put in place during welding of the low carbon steel are optimum for quality weld.

Effect of post-weld heat treatment on microstructure and corrosion properties of multi-layer super duplex stainless steel welds

2021 ◽  
Vol 63 (9) ◽  
pp. 791-796
Author(s):  
Lei Tian ◽  
Zhanqi Gao ◽  
Yongdian Han
Keyword(s):  
Heat Treatment ◽  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Welded Joints ◽  
Post Weld Heat Treatment ◽  
Super Duplex Stainless Steel ◽  
Corrosion Properties ◽  
Austenite Content ◽  
Mechanical And Corrosion Properties ◽  
Weld Heat

Abstract To investigate the influence of post-weld heat treatment on the microstructure and corrosion properties of super duplex stainless steel welded joints, multi-layer multi-pass welding of 2507 super duplex stainless steel by tungsten argon arc welding was performed using an ER2594 welding wire. The microstructures of the welded joints before and after post-weld heat treatment at 1150 °C, 1170 °C and 1190 °C were observed, and the mechanical and corrosion properties were tested. The post-weld heat treatment changed the austenite content and morphology of the welded joint and improved the corrosion resistance of different parts of the weld metal. The choice of various solution heat treatment temperatures affected the change in austenite content in the weld zone and the degree of diffusion and homogenization of the alloy elements. After post-weld heat treatment at 1170 °C, the two-phase ratios in each area of the weld were the most suitable and uniform, and the overall mechanical and corrosion properties of the joint were more uniform.

Technological features of autoclave molding of parts of complex configuration from В95оч alloy sheets

2021 ◽  
Author(s):  
Keyword(s):  
Heat Treatment ◽  
Technological Process ◽  
Aging Process ◽  
Sheet Material ◽  
High Strength ◽  
Spring Back ◽  
Corrosion Properties ◽  
Strength Alloy ◽  
Mechanical And Corrosion Properties ◽  
Wing Skin

The development is shown with the use of modeling the technological process of autoclave molding, combined with the aging process, for the manufacture of upper wing skins from sheets of "В95оч" high-strength alloy taking into account the spring back of the workpiece. The results of studies of indicators of mechanical and corrosion properties of the resulting product are presented. Keywords: autoclave molding, heat treatment, springback, upper wing skin, sheet material, "В95оч". [email protected]

Mechanical and Corrosion Properties of Ni-Free Austenitic Stainless Steel/Hydroxyapatite Nanocomposites

2009 ◽  
Vol 151 ◽  
pp. 213-216 ◽  
Author(s):  
Maciej Tulinski ◽  
Mieczyslaw Jurczyk
Keyword(s):  
Heat Treatment ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Stainless Steels ◽  
Bulk Material ◽  
Hard Tissue ◽  
Corrosion Properties ◽  
Ringer’S Solution ◽  
Tissue Replacement ◽  
Mechanical And Corrosion Properties

In the present work, a nanocrystalline nickel-free stainless steels as well as nickel-free stainless steel/hydroxyapatite nanocomposites have been synthesized by the combination of mechanical alloying (MA), heat treatment and nitriding. The microhardness of the final bulk material was studied using Vickers method. Corrosion potentiodynamic tests were performed in Ringer’s solution. The results show that nickel-free stainless steel/hydroxyapatite nanocomposites could be promising bionanomaterials for use as a hard tissue replacement implants.

scholarly journals Mechanical and Corrosion Studies of Friction Stir Welded Nano Al2O3 Reinforced Al-Mg Matrix Composites: RSM-ANN Modelling Approach

Symmetry ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 537
Author(s):  
Chandrashekar A. ◽  
B. V. Chaluvaraju ◽  
Asif Afzal ◽  
Denis A. Vinnik ◽  
Abdul Razak Kaladgi ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Metal Matrix ◽  
Corrosion Properties ◽  
Metal Matrix Nanocomposites ◽  
X Ray ◽  
Friction Stir ◽  
The Matrix ◽  
Mechanical And Corrosion Properties ◽  
Al2o3 Particles ◽  
Matrix Nanocomposites

Nano aluminum oxide was prepared by the combustion method using aluminum nitrate as the oxidizer and urea as a fuel. Characterization of synthesized materials was performed using SEM (scanning electron microscope), powder XRD (X-ray diffraction), FTIR (Fourier transform infrared spectroscopy), and TEM (transmission electron microscope). Al-Mg/Al2O3 (2, 4, 6, and 8 wt%) metal matrix nanocomposites were prepared by liquid metallurgy route-vertex technique. The homogeneous dispersion of nano Al2O3 particles in Al-Mg/Al2O3 metal matrix nanocomposites (MMNCs) was revealed from the field emission SEM analysis. The reinforcement particles present in the matrix were analyzed through energy-dispersive X-ray spectroscopy method. The properties (corrosion and mechanical) of the fabricated composites were evaluated. The mechanical and corrosion properties of the prepared nanocomposites initially increased and then decreased with the addition of nano Al2O3 particles in Al-Mg Matrix. The studies show that, the presence of 6 wt% of nano Al2O3 particles in the matrix improved the properties of other combinations of nano Al2O3 in the Al-Mg matrix material. Further, the Al-Mg/Al2O3 (6 wt%) MMNCs are joined by friction stir welding and evaluated for microstructural, mechanical, and corrosion properties. Al-Mg/Al2O3 MMNCs may find applications in the marine field. The response surface method (RSM) was used for the optimization of tensile strength, Young’s modulus, and microhardness of the synthesized material which resulted in a 95% of statistical confidence level. Artificial neural network (ANN) analysis was also carried out which perfectly predicted these two properties. The ANN model is optimized to obtain 99.9% accurate predictions by changing the number of neurons in the hidden layer.

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