Defect Formation of Gray Iron Casting

2009 ◽  
Vol 3 (4) ◽  
pp. 49-58 ◽  
Author(s):  
A. Diószegi ◽  
L. Elmquist ◽  
J. Orlenius ◽  
I. Dugic
2022 ◽  
Vol 35 (2) ◽  
Author(s):  
Blake C. Stewart ◽  
Haley R. Doude ◽  
Terry L. Taylor ◽  
Morgan B. Abney ◽  
Hongjoo Rhee

2016 ◽  
Vol 11 (2) ◽  
pp. 328-339 ◽  
Author(s):  
Alireza Modaresi ◽  
Azim Safikhani ◽  
Amir Mohammad Sedigh Noohi ◽  
Naser Hamidnezhad ◽  
Seyed Mostafa Maki

2010 ◽  
Vol 457 ◽  
pp. 416-421 ◽  
Author(s):  
Lennart Elmquist ◽  
Attila Diószegi ◽  
Tobias Björklind

The formation of shrinkage porosity is a concern in the production of high-quality gray iron castings. In this work, a geometry known to generate this type of defect was used to investigate some of the parameters that influence its formation. The geometry is based on the presence of a migrating hot spot that at the end of the solidification is located close to the interface between the casting and the mold. The occurrence of shrinkage porosity at this position was investigated and the cavities examined using a scanning electron microscope equipped with EDS. It is believed that this type of defect is in contact with the atmosphere during solidification. The risk for shrinkage porosity decreases with increasing carbon content. The effect of high levels of molybdenum and phosphorus was investigated and shown to influence the defect formation. Inoculation is used to control the nucleation and the effect of high levels of inoculants was also examined. The microstructure was investigated by the use of a color etching technique, and the quantification considered eutectic cell size and secondary dendrite arm spacing. The quantification was done on the microstructure in the vicinity of defects as well as in areas without porosity.


Author(s):  
H. Watanabe ◽  
B. Kabius ◽  
B. Roas ◽  
K. Urban

Recently it was reported that the critical current density(Jc) of YBa2Cu2O7, in the presence of magnetic field, is enhanced by ion irradiation. The enhancement is thought to be due to the pinning of the magnetic flux lines by radiation-induced defects or by structural disorder. The aim of the present study was to understand the fundamental mechanisms of the defect formation in association with the pinning effect in YBa2Cu3O7 by means of high-resolution electron microscopy(HRTEM).The YBa2Cu3O7 specimens were prepared by laser ablation in an insitu process. During deposition, a substrate temperature and oxygen atmosphere were kept at about 1073 K and 0.4 mbar, respectively. In this way high quality epitaxially films can be obtained with the caxis parallel to the <100 > SrTiO3 substrate normal. The specimens were irradiated at a temperature of 77 K with 173 MeV Xe ions up to a dose of 3.0 × 1016 m−2.


1985 ◽  
Vol 147 (11) ◽  
pp. 523 ◽  
Author(s):  
M.I. Klinger ◽  
Ch.B. Lushchik ◽  
T.V. Mashovets ◽  
G.A. Kholodar' ◽  
M.K. Sheinkman ◽  
...  

Author(s):  
I.A. Tserna ◽  
◽  
V.V. Bukhov ◽  

The paper presents the results of computer simulation of the process of de-formationforged chain wheels, combine harvester; the influence of the placement of the jumper outline for firmware on the processes of defect formation in forging.


2001 ◽  
Author(s):  
J. Zartman ◽  
V. Khare ◽  
A. Greenberg ◽  
M. Pekny ◽  
P. Todd ◽  
...  

Author(s):  
Vitaly М. Goritsky ◽  
◽  
Georgy R. Shneyderov ◽  
Eugeny P. Studenov ◽  
Olga A. Zadubrovskaya ◽  
...  

Determination of causes of crack-like defects in the heavy plate steel 09Г2С is a crucial task, the solution of which is aimed at improving the mechanical safety of oil storage steel vertical tanks. In order to determine the causes for the formation of a group of crack-like defects oriented towards rolling, revealed during grinding and magnetic inspection of the tank wall surface near the vertical weld, the analysis of the chemical composition and testing of the mechanical properties of heavy plate steel were carried out, including the determination of the anisotropy of impact toughness in the temperature range from +20 to –75 °С, analysis of metal microstructure in the area of defect formation on transversal sections and rolled surface. Impact bending tests of 09Г2С heavy plate steel after controlled rolling in longitudinal and transverse directions showed no anisotropy of impact toughness, as well as high purity of steel as for sulfur and titanium, which at higher content causes impact toughness anisotropy. The revealed features of metal microstructure near the defects made it possible to conclude that the crack-like defects were formed during the rolling of gas bubbles at the stage of preparing semi-finished rolled products for finishing rolling. One of the possible methods to prevent such defects from getting into finished rolled products is the use of automated systems of visual inspection of rolled products in the manufacturing process.


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