scholarly journals Effect of Mg Addition (in Zinc Bath) on Galvanized Sheet Quality

2013 ◽  
Vol 2 (6) ◽  
pp. 105-111 ◽  
Author(s):  
S K Shukla ◽  
M. Deepa ◽  
Santosh Kumar
Keyword(s):  
Zinc Bath ◽  
Mg Addition

Direct observation of Fe-Al-Zn ternary intermetallic compound and its transformation during the early stage of hot-dip galvanizing

1993 ◽  
Vol 51 ◽  
pp. 1116-1117
Author(s):  
C. S. Lin ◽  
W. A. Chiou ◽  
M. Meshii
Keyword(s):  
Intermetallic Compound ◽  
Reaction Rate ◽  
Diffusion Rate ◽  
Early Stage ◽  
Zinc Bath ◽  
Steel Sheets ◽  
Direct Observations ◽  
Solid Iron ◽  
Iron And Zinc ◽  
Ternary Intermetallic Compound

The galvannealed steel sheets have received ever increased attention because of their excellent post-painting corrosion resistance and good weldability. However, its powdering and flaking tendency during press forming processes strongly impairs its performance. In order to optimize the properties of galvanneal coatings, it is critical to control the reaction rate between solid iron and molten zinc.In commercial galvannealing line, aluminum is added to zinc bath to retard the diffusion rate between iron and zinc by the formation of a thin layer of Al intermetallic compound on the surface of steel at initial hot-dip galvanizing. However, the form of this compound and its transformation are still speculated. In this paper, we report the direct observations of this compound and its transformation.The specimens were prepared in a hot-dip simulator in which the steel was galvanized in the zinc bath containing 0.14 wt% of Al at a temperature of 480 °C for 5 seconds and was quenched by liquid nitrogen.

The Effect of Mg Addition and Manufacturing Conditions on the Interfacial Reactions between Al and CNT in Al-CNT Pellets

2013 ◽  
Vol 51 (5) ◽  
pp. 385-391 ◽  
Author(s):  
Gue-Serb Cho ◽  
Jung-Kyu Lim ◽  
Sonn-Yool Choi ◽  
Kyong-Hwan Choe ◽  
Sang-Sub Kim
Keyword(s):  
Interfacial Reactions ◽  
Mg Addition

scholarly journals Part II. Model for the Protective Coating Formation During Hot Dip Galvanizing/ Część II. Model Formowania Powłoki Ochronnej Podczas Cynkowania Ogniowego

2014 ◽  
Vol 59 (4) ◽  
pp. 1393-1404 ◽  
Author(s):  
W. Wołczynski ◽  
Z. Pogoda ◽  
G. Garzeł ◽  
B. Kucharska ◽  
A. Sypien ◽  
...  
Keyword(s):  
Phase Diagram ◽  
Mass Balance ◽  
Protective Coating ◽  
Mathematical Description ◽  
Ternary Phase ◽  
Ternary Phase Diagram ◽  
Solute Redistribution ◽  
Zinc Bath ◽  
Flux System ◽  
Coating Formation

Abstract A mathematical description for the (Zn) - coating formation with the presence of flux in the zinc bath is presented. This description includes the progressive vanishing of the products of the flux disintegration. A function which expresses the flux vanishing is formulated. The solidification of some phase sub-layers in the (Zn) - coating is considered with the use of a hypothetical pseudo-ternary phase diagram Fe-Zn-flux. Some relationships are formulated to define the varying Zn - solute redistribution as observed across the sub-layers. The relationships are based on the mass balance analyzed for the coating / bath / flux system. An amount of the growing phase in a given sub-layers is also defined mathematically.

scholarly journals Enzymatic Synthesis of Isopropyl Acetate by Immobilized   Bacillus cereus Lipase in Organic Medium

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Madan Lal Verma ◽  
Wamik Azmi ◽  
Shamsher Singh Kanwar
Keyword(s):  
Acetic Acid ◽  
Bacillus Cereus ◽  
Water Activity ◽  
Molecular Sieves ◽  
Immobilized Lipase ◽  
Molar Ratio ◽  
Ester Synthesis ◽  
Initial Water ◽  
Isopropyl Acetate ◽  
Mg Addition

Selective production of fragrance fatty acid ester from isopropanol and acetic acid has been achieved using silica-immobilized lipase of Bacillus cereus MTCC 8372. A purified thermoalkalophilic extracellular lipase was immobilized by adsorption onto the silica. The effects of various parameters like molar ratio of substrates (isopropanol and acetic acid; 25 to 100 mM), concentration of biocatalyst (25–125 mg/mL), reaction time, reaction temperature, organic solvents, molecular sieves, and initial water activity were studied for optimal ester synthesis. Under optimized conditions, 66.0 mM of isopropyl acetate was produced when isopropanol and acetic acid were used at 100 mM: 75 mM in 9 h at 55°C in n-heptane under continuous shaking (160 rpm) using bound lipase (25 mg). Addition of molecular sieves (3 Å  × 1.5 mm) resulted in a marked increase in ester synthesis (73.0 mM). Ester synthesis was enhanced by water activity associated with pre-equilibrated saturated salt solution of LiCl. The immobilized lipase retained more than 50% of its activity after the 6th cycle of reuse.

Critical concentration of Mg addition for plastic instabilities in Al–Mg alloys

2000 ◽  
Vol 15 (5) ◽  
pp. 1037-1040 ◽  
Author(s):  
N. Q. Chinh ◽  
F. Csikor ◽  
Zs. Kovács ◽  
J. Lendvai
Keyword(s):  
Room Temperature ◽  
Loading Rate ◽  
Critical Concentration ◽  
Solute Concentration ◽  
Mg Alloys ◽  
Depth Sensing ◽  
Solute Content ◽  
Mg Addition ◽  
Constant Loading Rate ◽  
Al Mg Alloys

Plastic instabilities were investigated by the depth-sensing microhardness test in binary high-purity Al–Mg alloys with different Mg contents. During the tests the applied load was increased from 0 to 2000 mN at constant loading rate. The instabilities appeared as characteristic steps in the load–depth curves during indentation. It was shown that the occurrence and development of the plastic instabilities depend strongly on the solute content. Furthermore, the plastic instabilities occurred only when the solute concentration was larger than a critical value, C0. From room-temperature tests on Al–Mg alloys, C0 was found to be 0.86 wt% Mg. The critical concentration, which is necessary to get plastic instabilities, was also interpreted theoretically.

scholarly journals Effect of Mg Treatment on the Nucleation and Ostwald Growth of Inclusions in Fe-O-Al-Mg Melt

Materials ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3355
Author(s):  
Yutang Li ◽  
Linzhu Wang ◽  
Chaoyi Chen ◽  
Junqi Li ◽  
Xiang Li
Keyword(s):  
Nucleation Rate ◽  
Ostwald Ripening ◽  
Critical Size ◽  
Early Stage ◽  
Inclusion Size ◽  
Nucleation Theory ◽  
Mg Addition ◽  
Homogeneous Nucleation Theory ◽  
Mg Melt ◽  
Size Of Nuclei

This study aimed to investigate the effect of Mg treatment on the nucleation and ostwald growth of inclusions. Deoxidized experiments with Al (0.05%Al) and Al-Mg (0.05%Al + 0.03%Mg) were carried out at 1873 K, and the composition, number, and size of inclusions were studied as a function of holding time. Homogeneous nucleation theory and ostwald ripening were utilized to calculate the nucleation rate, the critical size of nuclei, and coarsening rate of inclusions. The results show that small inclusions were more easily found in the steels with Al-Mg complex deoxidation, and the number of inclusions with Al-Mg complex deoxidation is larger at an early stage of deoxidation. The critical size of nuclei increases in the order of MgAl2O4 (0.3–0.4 nm) < Al2O3 (0.4–0.6 nm), and the nucleation rate increases in the order of Al2O3 (1100 cm−3 s−1) < MgAl2O4 (1200 cm−3s−1), which is consistent with the experimental results. Moreover, the coarsening rate of MgAl2O4 inclusions was smaller than Al2O3 inclusions in both the value of kd(cal.) from ostwald growth and the value of kd(obs.) from inclusion size. The effect of Mg addition on coarsening of inclusion was analyzed and their mechanism was discussed based on ostwald ripening theory and Factsage calculation.

scholarly journals PRODUCTION OF SODIUM SILICATE FROM RICE HUSK ASH WITH REGULATORY SETS MAGNESIUM

Tibuana ◽  
2020 ◽  
Vol 3 (01) ◽  
pp. 47-52
Author(s):  
Yanatra budi Pramana ◽  
M. Amin Pahlevi ◽  
Zhulianto Ashari ◽  
M. Fariz Effendi ◽  
Fibra Gilang Ramadhan
Keyword(s):  
Sodium Silicate ◽  
Rice Husk ◽  
Rice Husk Ash ◽  
Silica Content ◽  
Cosmetic Products ◽  
Rice Husks ◽  
Mg Addition ◽  
Increase Silica Content

Utilization of rice husks in Indonesia in general is still very limited. Utilization of silica contained in rice husk ash, which has been used, among others, in the manufacture of sodium silicate. Silica compounds themselves can be used in and manufacturing basic materials for electronic and ceramic equipment, glass, rubber, cosmetic products, and pharmaceuticals. The addition of Mg can increase the silica content (SiO2) in rice husk ash. The best results show an effective Mg ratio of Mg addition to increase silica content is 1: 1. produces the highest amount of silica which is 58.12% of the rice husk ash with a size of 140 mesh

scholarly journals Effect of Mg Addition on the Structure and Properties of Al-4.5 Cu-3.4 Fe <i>In-Situ</i> Cast Composite

2020 ◽  
Vol 08 (03) ◽  
pp. 66-73
Author(s):  
Nurul Afsar Chowdhury ◽  
Md. Arifur Rahman Khan ◽  
Sajib Aninda Dhar
Keyword(s):  
Structure And Properties ◽  
Cast Composite ◽  
Mg Addition
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