Study on the Influences on Microstructure and Properties of High-Strength Grey Cast Iron in Addition to Alloying Elements Nb

2013 ◽  
Vol 800 ◽  
pp. 221-224
Author(s):  
Jun Tao Zhang ◽  
Feng Zhang Ren

The increase of the strength of gray cast iron is mainly depended on alloying. However, with the improvement of strength, its processing performance will always decrease. So three different gray cast irons are studied in this experiment, including adding 0.1% Nb elements, adding 0.2% Nb elements and adding 0.3% Nb elements, to investigate the Nbs effect to the mechanical performance of gray cast iron, we adopt Dynamic Strain Amplifier to measure cutting force to evaluate processing performance, use Optical Microscope and Electron Microscopy observe each samples organization, explains the relationship between Nbs content and the mechanical and processing performance of gray cast iron from micro-level. Finally, we draw the conclusion: when the Nb comes to 0.3 percent, the appearance of E-type graphite and Nb carbide durum granular will greatly decrease its processing performance.

Alloy Digest ◽  
2021 ◽  
Vol 70 (9) ◽  

Abstract ISO 185/JL/350 is a higher-tensile-strength gray cast iron that has a pearlitic matrix, and a tensile strength of 350–450 MPa (51–65 ksi), when determined on test pieces machined from separately cast, 30 mm (1.2 in.) diameter test bars. It provides a combination of high strength while still maintaining good thermal conductivity compared with other types of cast iron. This grade approaches the maximum tensile strength attainable in gray cast iron. Applications therefore tend to be confined to those where thermal conductivity requirements in service preclude the use of one of the other higher-strength materials such as spheroidal graphite cast irons, which have inferior thermal properties. This datasheet provides information on composition, physical properties, and tensile properties. It also includes information on wear resistance as well as casting and heat treating. Filing Code: CI-85. Producer or source: International Organization for Standardization.


2017 ◽  
Vol 62 (2) ◽  
pp. 1113-1117
Author(s):  
Seung-Yeon Park ◽  
J.H. Kim ◽  
S.J. Seo ◽  
J.S. On ◽  
K.M. Lim

AbstractIn this study, we have developed the manufacturing technology for high strength gray cast irons by using the spent permanent magnet scraps. The cast specimen inoculated by using a spent magnet scraps showed the excellent tensile strength up to 306MPa. This tensile strength value is 50MPa higher than that of the specimen cast without inoculation, and is similar to that of the specimen inoculated by using the expensive misch-metal. These superior mechanical properties are attributed to complex sulfides created during solidification that promote the formation and growth of Type-A graphite. It is therefore concluded that spent magnets scrap can provide an efficient and cost-effective inoculation agent for the fabrication of high-performance gray cast iron.


Alloy Digest ◽  
2021 ◽  
Vol 70 (6) ◽  

Abstract ISO 185/JL/300 is a higher-tensile-strength gray cast iron that has a pearlitic matrix; it has a tensile strength of 300–400 MPa (44–58 ksi), when determined on test pieces machined from separately cast, 30 mm (1.2 in.) diameter test bars. It provides high strength while still maintaining good thermal conductivity compared with other types of cast iron. This grade approaches the maximum tensile strength attainable in gray cast iron. Applications therefore tend to be confined to those where thermal conductivity requirements in service preclude the use of one of the other higher-strength materials such as spheroidal graphite cast irons, which have inferior thermal properties. This datasheet provides information on composition, physical properties, and tensile properties. It also includes information on casting and heat treating. Filing Code: CI-82. Producer or source: International Organization for Standardization.


Author(s):  
D. T. Oloruntoba ◽  
O. S. Adesina ◽  
O. F. Abraham ◽  
K. J. Akinluwade

This research focused on the corrosion behavior of gray cast iron and aluminum in alkaline medium (0.5 M NaOH) with and without inhibitor (water hyacinth Eichhornia crassipes extract) of varying concentrations of 5%, 10%, 15%, 20% and 25%. The corrosion rates of the metal samples were investigated using the weight loss and electrochemical methods alongside the formulation of a dispersant using readily available chemicals to develop a colloidal solution of the extract produced by hot water digestion of the water hyacinth plant leaves. The metallography tests of control samples as well as the most and least corroded samples were carried out using Optical Microscope (OM). The results revealed that the aluminum resulted in minimum corrosion rate of 0.000483 mg/mm2/yr with inhibitor efficiency of 98.93% obtained for sample A5 (25% extract from water hyacinth) while for the gray cast iron, a minimum corrosion rate of -4.4E-05 mg/mm2/yr with inhibitor efficiency of 566.6% obtained for sample C3 (15% extract from water hyacinth). The electrochemical result of aluminum showed increase in corrosion potential from -1.494 VAg/AgCl to -1.482 V Ag/AgCl and that of gray cast iron from -0.5436 VAg/AgCl to -0.2839 VAg/AgCl upon increase in inhibitor concentration. Therefore, the use of water hyacinth (Eichhornia crassipes)extract reduced the corrosion or dissolution rate of gray cast iron and aluminum in (NaOH) sodium hydroxide medium.


2010 ◽  
Vol 660-661 ◽  
pp. 106-111
Author(s):  
José Vitor C. Souza ◽  
Maria do Carmo de Andrade Nono ◽  
João Paulo Barros Machado ◽  
Olivério Moreira Macedo Silva ◽  
F.C.L. Melo ◽  
...  

Silicon nitride cutting tools have been used successfully for machining hard materials, like: cast irons, nickel based alloys, etc. However these cutting tools with diamond coating present little information on dry turning operations of gray cast iron. In the present work, Si3N4 square inserts was developed, characterized and subsequently coated with diamond for dry machining operations on gray cast iron. All experiments were conducted with replica. It was used a 1500, 3000, 4500 m cutting length, feed rate of 0.33 mm/rev and keeping the depth of cut constant and equal to 1 mm. The results show that wear in the tool tips of the Si3N4 inserts, in all cutting conditions, was caused by both mechanical and chemical processes. To understand the tool wear mechanisms, a morphological analysis of the inserts, after experiments, has been performed by SEM and optical microscopy. Diamond coated PVD inserts showed to be capable to reach large cutting lengths when machining gray cast iron.


2013 ◽  
Vol 750-752 ◽  
pp. 450-453
Author(s):  
Jun Tao Zhang ◽  
Feng Zhang Ren

The formation of the microstructure of gray cast iron is a complex process. There remains many unanswered questions about the process. Using annealing method, the first crystallized primary austenite dendrites from the molten iron was displayed. The room temperature microstructures of gray cast iron with and without Cu, Cr addition were studied. The relationship between microstructure and mechanical property was discussed. The results show that the amount of primary austenite dendrites of the multi-alloyed gray cast iron increases significantly and the secondary dendrite arm spacing seems narrow. The microstructure at room temperature is fine and homogeneous. Tensile strength increases significantly, up to 300MPa with adding 0.58%Cu and 0.29%Cr.


2008 ◽  
Vol 591-593 ◽  
pp. 565-571 ◽  
Author(s):  
Olivério Moreira Macedo Silva ◽  
Maria do Carmo de Andrade Nono ◽  
José Vitor C. Souza ◽  
M.V. Ribeiro

The α-SiAlON ceramic cutting tool insert is developed. Silicon nitride and additives powders are pressed and sintered in the form of cutting tool inserts at temperature of 1900 oC. The physics and mechanical properties of the inserts like green density, weight loss, relative density, hardness and fracture toughness are evaluated. Machining studies are conducted on grey cast iron workpiece to evaluate the performance of α-SiAlON ceramic cutting tool. In the paper the cutting tool used in higher speed showed an improvement in the tribological interaction between the cutting tools and the grey cast iron workpiece resulted in a significant reduction of flank wear and roughness, because of better accommodation and the presence of the graphite in gray cast iron. The above results are discussed in terms of their affect at machining parameters on gray cast iron.


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