scholarly journals Shaping optimal zinc coating on the surface of high-quality ductile iron casting. Part I – Moulding technologies vs. zinc coating

2017 ◽  
Vol 62 (1) ◽  
pp. 385-390
Author(s):  
A. Szczęsny ◽  
D. Kopyciński ◽  
E. Guzik
Keyword(s):  
Surface Layer ◽  
Ductile Iron ◽  
Metal Matrix ◽  
Surface Condition ◽  
Zinc Coating ◽  
Casting Surface ◽  
Iron Castings ◽  
Coating Formation ◽  
Ductile Iron Casting

Abstract Studies have demonstrated that in the process of hot dip galvanizing the decisive influence on the mechanism of zinc coating formation and properties has the quality of the mechanically untreated (raw) surface layer of the galvanized product. The terms “casting surface layer” denote various parameters of the microstructure, including the type of metal matrix, the number of grains and the size of graphite nodules, possible presence of hard spots (the precipitates of eutectic cementite) and parameters of the surface condition. The completed research has allowed linking the manufacturing technology of ductile iron castings with the process of hot dip galvanizing.

scholarly journals Effect of the Surface Layer of Iron Casting on the Growth of Protective Coating During Hot-Dip Galvanizing

2016 ◽  
Vol 16 (1) ◽  
pp. 25-28 ◽  
Author(s):  
D. Kopyciński ◽  
E. Guzik ◽  
A. Szczęsny
Keyword(s):  
Surface Roughness ◽  
Protective Coating ◽  
Ductile Iron ◽  
Zinc Coating ◽  
Roughness Parameters ◽  
Casting Surface ◽  
Iron Casting ◽  
Kinetics Of ◽  
Ductile Iron Casting

Abstract The paper presents the results of investigations of the growth of protective coating on the surface of ductile iron casting during the hot-dip galvanizing treatment. Ductile iron of the EN-GJS-600-3 grade was melted and two moulds made by different technologies were poured to obtain castings with different surface roughness parameters. After the determination of surface roughness, the hot-dip galvanizing treatment was carried out. Based on the results of investigations, the effect of casting surface roughness on the kinetics of the zinc coating growth was evaluated. It was found that surface roughness exerts an important effect on the thickness of produced zinc coating.

scholarly journals The Effect of the Number of Eutectic Grains on Coating Growth During Hot Dip Galvanising of Ductile Iron Castings

2014 ◽  
Vol 14 (1) ◽  
pp. 67-70
Author(s):  
D. Kopyciński ◽  
E. Guzik ◽  
A. Szczęsny
Keyword(s):  
Cross Sections ◽  
Ductile Iron ◽  
Metal Matrix ◽  
Zinc Coating ◽  
Annealing Treatment ◽  
Test Results ◽  
Iron Castings ◽  
Iron Grade ◽  
Kinetics Of ◽  
Coating Growth

Abstract Studies were conducted on a zinc coating produced on the surface of ductile iron grade EN-GJS-500-7 to determine the eutectic grain effect. For this purpose, castings with a wall thickness of 5 to 30 mm were made and the resulting structure was examined. To obtain a homogeneous metal matrix, samples were subjected to a ferritising annealing treatment. To enlarge the reaction surface, the top layer was removed from casting by machining. Then hot dip galvanising treatment was performed at 450°C to capture the kinetics of growth of the zinc coating (in the period from 60 to 600 seconds). Analysing the test results it was found that within the same time of hot dip galvanising, the differences in the resulting zinc coating thickness on samples taken from castings with different wall cross-sections were small but could, particularly for shorter times of treatment, reduce the continuity of the alloyed layer of the zinc coating.

scholarly journals New Possibilities of Shaping the Surface Properties in Austempered Ductile Iron Castings

2013 ◽  
Vol 13 (1) ◽  
pp. 103-106 ◽  
Author(s):  
D. Myszka
Keyword(s):  
Surface Layer ◽  
Surface Properties ◽  
Ductile Iron ◽  
Shot Peening ◽  
Austempered Ductile Iron ◽  
Protective Atmosphere ◽  
Detonation Spraying ◽  
Iron Castings ◽  
Recent Developments ◽  
Commercial Applications

Abstract The paper presents recent developments concerning the formation of surface layer in austempered ductile iron castings. It was found that the traditional methods used to change the properties of the surface layer, i.e. the effect of protective atmosphere during austenitising or shot peening, are not fully satisfactory to meet the demands of commercial applications. Therefore, new ways to shape the surface layer and the surface properties of austempered ductile iron castings are searched for, to mention only detonation spraying, carbonitriding, CVD methods, etc.

scholarly journals PARTICULARS APPLICATION OF DUCTILE IRON CASTINGS

2014 ◽  
Author(s):  
Larisa Ivanovna Putyatina ◽  
Larisa Andreevna Timofeeva
Keyword(s):  
Heat Treatment ◽  
Ductile Iron ◽  
Thin Sections ◽  
Iron Castings ◽  
Lamellar Graphite ◽  
Main Factors ◽  
Relationship Of ◽  
The Relationship ◽  
Free Cementite

The results of analysis of the relationship of structure and mechanical properties of ductile cast ironpots with globular graphite form, experience and perspectives of their industrial application. It is shown thatthe growth in the production of castings of ductile iron is caused exclusively by a favorable combination ofphysical, mechanical, operational and technological properties of this material, as well as economicconsiderations.The main factors regulating the cast structure and level of physical, mechanical and operationalcharacteristics of ductile iron are: the quality of the initial melt modification modes (including composition,quantity, method and sequence of input and additives), chemical composition and rate of solidification of themetal.Heat treatment of ductile iron is more effective than iron with lamellar graphite , since graphitespherical than weakens the metal substrate than the plate . Castings from nodular iron are exposed tovarious types of heat treatment. The purpose of heat treatment - structurally free cementite decomposition inrelatively thin sections of the casting ( graphitizing joke ) or hardening of pearlite matrix ( normalization).Can be used combined heat treatment, the purpose of pursuing the expansion of structurally free cementitewith subsequent normalization.

Effect of Yttrium and Magnesium Segregation on Microstructure and Mechanical Properties of Heavy Section Ductile Iron Castings

2011 ◽  
Vol 295-297 ◽  
pp. 1010-1016 ◽  
Author(s):  
Wei Ping Chen ◽  
Zhe Liu ◽  
Yu Deng ◽  
Jie Luo ◽  
Yong Cheng Chen
Keyword(s):  
Mechanical Properties ◽  
Ductile Iron ◽  
Magnesium Content ◽  
Solidification Mode ◽  
Iron Casting ◽  
Iron Castings ◽  
Microstructure And Mechanical Properties ◽  
Chunky Graphite ◽  
Main Factor ◽  
Ductile Iron Casting

Ductile iron specimen with dimensions of Φ590mm×800mm were prepared by treating the melt with an yttrium-containing nodulizer. Cooling curves at four locations____the center location, the location 85mm distant from the center, the location 170mm distant from the center and the location 255mm distant from the center of the heavy ductile iron casting Φ590mm×800mm was obtained. The effect of yttrium and magnesium on microstructure and mechanical properties was investigated, and the factors on the distribution of chunky graphite in the specimen were discussed as well. The results show that the largest amount of chunky graphite and the lowest mechanical properties appear at the location 170mm distant from the center. Excessive yttrium and magnesium content at the location 170mm distant from the center is the main factor for the large amount of chunky graphite. The characteristics of the solidification mode____pasty solidification and the considerably long solidification of the casting are the basic reasons for the distribution of chunky graphite of the heavy ductile iron casting Φ590mm×800mm.

scholarly journals Experimental Study Regarding the Possibility of Blocking the Diffusion of Sulfur at Casting-Mold Interface in Ductile Iron Castings

Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 673
Author(s):  
Denisa Anca ◽  
Iuliana Stan ◽  
Mihai Chisamera ◽  
Iulian Riposan ◽  
Stelian Stan
Keyword(s):  
Surface Layer ◽  
Ductile Iron ◽  
Steel Sheet ◽  
Sheet Thickness ◽  
Superficial Layer ◽  
Iron Casting ◽  
Casting Mold ◽  
Iron Castings ◽  
Sulfur Diffusion ◽  
Structure Evaluation

The main objective of this work is to investigate the mechanism of sulfur diffusion from the mold (sand resin P-toluol sulfonic acid mold, sulfur-containing acid) in liquid cast iron in order to limit the graphite degeneration in the surface layer of iron castings. A pyramid trunk with square section samples was cast. On the opposite side of the feed canal of the samples, steel sheets with different thicknesses (0.5, 1, and 3 mm) were inserted with the intention of blocking the diffusion of sulfur from the mold into the cast sample during solidification. The structure evaluation (graphite and matrix) in the surface layer and the casting body was recorded. The experimental results revealed that by blocking the direct diffusion of sulfur at the mold-casting interface, a decrease of the demodified layer thickness (for 0.5 mm steel sheet thickness) is obtained until its disappearance (for steel sheet thicknesses of more than 1 mm). The paper contains data that may be useful in elucidating the mechanism of graphite degeneration in the superficial layer of ductile iron castings. Based on the obtained results, we recommend using such barriers on the metal-mold interface, which are able to limit sulfur diffusion from the mold/core materials into the iron castings, in order to limit or even cease graphite degeneration in the Mg-treated surface iron casting layer. The paper presents additional data related to the interaction of sulfur at the ductile iron casting-mold interface previously analyzed.

A Study on Ductile Iron Production without the Use of Feeders

2010 ◽  
Vol 457 ◽  
pp. 499-504
Author(s):  
Vasilios Fourlakidis
Keyword(s):  
Thermal Analysis ◽  
Ductile Iron ◽  
Shrinkage Porosity ◽  
Cooling Curves ◽  
Pouring Temperature ◽  
Iron Castings ◽  
Shrinkage Defects ◽  
Microstructure Examination ◽  
Solidification Parameters ◽  
Ductile Iron Casting

This paper investigates the effects of graphite added as a conditioner, of Lantanum containing nodulariser and of pouring temperature on the formation of shrinkage porosity in ductile iron casting with an eutectic composition. In this experiment for each heat the cooling curves were recorded by the use of Quick-Cups (thermal analysis cups) and different solidification parameters such as TElow, GRF1, GRF2 and TS were calculated and compared with the porosity which was found from the microstructure examination. The results show that there is a good correlation between the amount of the shrinkage formation and the thermal analysis values. Also this experiment confirm that by using certain treating elements and pouring temperature which was between 1340-1350°C it is possible to eliminate the shrinkage defects in ductile iron castings without using feeders.

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