Microstructural Observation of SiC Surface Alloyed Carbon Steel

2011 ◽  
Vol 308-310 ◽  
pp. 2565-2568
Author(s):  
Chang Qing Guo
Keyword(s):  
Casting Process ◽  
Compound Layer ◽  
Optical Microscope ◽  
Carbon Steels ◽  
Expanded Polystyrene ◽  
Surface Compound ◽  
Polystyrene Spheres ◽  
Transitional Layer ◽  
Sic Particles ◽  
Fine Pearlite

EPS (expanded polystyrene spheres) template with a 5 mm coating on a surface that is mainly consisted of SiC particles are prepared. Carbon steels are then poured in the templates using V-EPC (Vacuum Expandable Pattern Casting) process. The microstructures are observed and analyzed using optical microscope, SEM and EDS. Macrostructural observation showed that the surface alloyed zone is dense and there are no obvious defects, such as gas bubbles, occluded gas holes and delimitation. Microstructural investigations indicated that the samples from top to bottom are obviously consisted of three different layers, i.e., the surface compound layer, the interim transitional layer and the bottom matrix layer. SiC particles are totally decomposed during infiltration. The microstructures in the surface compound layer are consisted of a large amount of graphite flakes, carbides, Si rich ferrites and dendritic pearlites. There is a fine pearlite strip at the top of the transitional layer and small amounts of carbide particles within the matrix grains and net carbides at the grain boundaries can be also observed in this layer.

Microstructural Observation of Ni-WC Surface Alloyed Carbon Steel

2011 ◽  
Vol 335-336 ◽  
pp. 58-62
Author(s):  
Chang Qing Guo ◽  
Qi Huan Wang
Keyword(s):  
Transitional Zone ◽  
Optical Microscope ◽  
Carbide Precipitation ◽  
Carbon Steels ◽  
Expanded Polystyrene ◽  
Polystyrene Spheres ◽  
Transitional Layer ◽  
The Matrix ◽  
Fine Pearlite ◽  
Carbide Particles

EPS (expanded polystyrene spheres) templates with thickness of a 10 mm coating on a surface that is mainly consisted of Ni-WC particles, are prepared. Carbon steels containing 0.45C%wt are then cast in the templates using V-EPC process (vacuum expandable pattern casting), forming the surface alloyed steels. The microstructures are observed and analyzed using optical microscope, SEM and EDS. Macrostructural observation showed that the surface alloyed zone is dense and there is no obvious defects, such as gas bubbles, occluded gas holes and delimitation. Microstructural investigations indicate that the samples from top to bottom are obviously consisted of three different zones, i.e., the top alloyed zone, the interim transitional zone and the bottom matrix zone. Ni-WC particles are totally decomposed during the molten steel infiltration. The microstructures in the surface alloyed zone are consisted of small amounts of fine WC+W2C carbides, large amounts of M3C+M7C3 carbides and dendritic matrix. There is a fine pearlite strip at the top of the transitional layer. Small amounts of carbide particles within the matrix grains and net carbide precipitation in the grain boundaries at the transitional zone can be observed.

Fabrication & Microstructure of TiB2+TiC Duplex Particulates Reinforced Carbon Steel Matrix Surface Composite

2013 ◽  
Vol 575-576 ◽  
pp. 198-202
Author(s):  
Chang Qing Guo
Keyword(s):  
Carbon Steel ◽  
Uniform Distribution ◽  
Compound Layer ◽  
Steel Matrix ◽  
Surface Compound ◽  
Transitional Layer ◽  
Composite Matrix ◽  
Microstructural Investigation ◽  
Surface Composite ◽  
Matrix Surface

This paper presents a novel fabrication process that combines SHS with V-EPC (vacuum expandable pattern casting) and microstructural features of TiB2+TiC duplex particulates reinforced surface composite with carbon steel matrix. Macro structural observation shows that the surface composite is dense and there are no obvious defects. Microstructural investigation demonstrates that the composite from surface to core is consisted of three different layers, i.e., the top surface compound layer, the interim transitional layer and the bottom carbon steel matrix. A large amount of fine TiB2 and TiC duplex particles are evenly distributed in the composite matrix, while the concentration are significantly decreased and non-uniform distribution increased for these particles in the interim layer.

The Influence of Oxide Inclusion on the Refinement of Bainite and Toughness in HAZ for Low Carbon Steels

2013 ◽  
Vol 651 ◽  
pp. 163-167
Author(s):  
Shu Rui Li ◽  
Xue Min Wang ◽  
Xin Lai He
Keyword(s):  
Mechanical Properties ◽  
Acicular Ferrite ◽  
Oxide Inclusion ◽  
Optical Microscope ◽  
Carbon Steels ◽  
Low Carbon ◽  
Low Carbon Steels ◽  
The Core ◽  
Ti Oxides ◽  
Bainitic Steels

The influence of Ti oxide on the toughness of heat affected zone for low carbon bainitic steels has been investigated. The optical microscope, SEM and TEM were used to analyze the composition, size and distribution of the inclusions, and the microstructure and mechanical properties after welding thermal simulation were also investigated. The effect of Ti oxide inclusion on the transformation of acicular ferrite has also been studied. The results show that after the melting with Ti dioxide technique the inclusion is complex, in the core is Ti oxides about 1-3 micron and around it is MnS. It has been found the acicular ferrite can nucleate at the inclusions and the Ti oxide inclusion will promote the nucleation of acicular ferrite, and the acicular ferrite will block the growth of bainite. Therefore by introducing the Ti oxide in the steels the microstructure of HAZ could be refined markedly therefore the toughness of HAZ can be improved evidently.

scholarly journals Corrosion investigations of Al-Si casting alloys in 0.6 M NaCl solution

2021 ◽  
Vol 41 (3) ◽  
Author(s):  
Sunčana Smokvina Hanza ◽  
Ladislav Vrsalović ◽  
Lovro Štic ◽  
Lovro Liverić
Keyword(s):  
Potentiodynamic Polarization ◽  
Electrochemical Behavior ◽  
Die Casting ◽  
Electrochemical Corrosion ◽  
Microstructural Characterization ◽  
Casting Process ◽  
Corrosion Current ◽  
Optical Microscope ◽  
Open Circuit ◽  
Polarization Measurements

This paper presents results of the corrosion investigations of specimens made from finished parts for the automotive industry, produced by high-pressure die casting and gravity die casting process of six Al-Si alloys (40000 series). Open circuit potential and potentiodynamic polarization measurements have been performed using a potentiostat with three-electrode set-up in 0.6 M NaCl naturally aerated solution. Microstructural characterization before and after electrochemical investigations has been carried out with optical microscope to establish the connection between microstructure and corrosion parameters of investigated alloys and to analyze and record surface changes of each sample due to electrochemical corrosion. All alloys show good corrosion resistance, which manifests with low values of corrosion rates, calculated from the corrosion current densities obtained from potentiodynamic polarization measurements. Differences in electrochemical behavior appear due to the distinctions in their chemical composition and microstructure. The type of casting process does not affect electrochemical behavior of Al-Si alloys.

Development of Steel Wire Rope – Reinforced Aluminium Composite for Armour Material Using the Squeeze Casting Process

2011 ◽  
Vol 277 ◽  
pp. 27-35 ◽  
Author(s):  
Dwi Rahmalina ◽  
Bondan Tiara Sofyan ◽  
Bambang Suharno ◽  
Eddy S. Siradj
Keyword(s):  
Squeeze Casting ◽  
Steel Wire ◽  
High Carbon Steel ◽  
Casting Process ◽  
Optical Microscope ◽  
Wire Rope ◽  
Aluminium Composite ◽  
Ballistic Properties ◽  
Semi Solid ◽  
Squeeze Casting Process

Steel wire rope – reinforced aluminium composite - has been developed to improve the ballistic properties and mobility of armour material. Critical to obtaining ballistic resistance is that the materials must be sufficiently hard and strong, especially at the surface where a projectile will first make impact. To obtain this resistance, aluminium alloys can be strengthened by adding Cu and Mg. This research studied the ballistic properties of aluminium composites with varied Cu and Mg content. The matrix used in this study was an Al-7Si master alloy with 0.08-1.03 wt. % Mg and 0.05-3.75 wt. % Cu, both independently and in combination. A high carbon steel wire rope was used as strengthening material. The samples were produced through the squeeze casting process with a pressure of 1 MPa at semi-solid melting temperatures of 590-610 °C. The slab was then rolled for 10 % reduction to increase the hardness. Ballistic testing was performed in accordance with ASTM F1233 by using a 9 mm calibre projectile and 900 direction. Micro structural observation was conducted in the as-cast and ballistic samples, performed with optical microscope and scanning electron microscope (SEM). The results showed that squeeze casting may improve interfacial wettability and reduce void. The increase in Mg resulted in the decline of interfacial voids, but Cu addition tended to increase them. The aluminium armour was able to withstand a 9 mm calibre projectile, although some cracks were visible. The wire rope was not effective in stopping the penetration of a 7.62 mm calibre projectile.

Atomic Force Microscopy of Annealed Plain Carbon Steels

2015 ◽  
Author(s):  
Surendra Kumar Gupta ◽  
Patricia Iglesias Victoria
Keyword(s):  
Atomic Force Microscopy ◽  
Optical Microscopy ◽  
Interlamellar Spacing ◽  
Lamellar Spacing ◽  
Optical Microscope ◽  
Carbon Steels ◽  
Force Microscopy ◽  
Atomic Force

Microstructure of annealed plain carbon steels is examined using optical microscopy. When the inter-lamellar spacing in pearlite is small, optical microscope at 1000X is unable to resolve the ferrite and cementite lamellae. In hyper-eutectoid steels, cementite in pearlite appears as darker phase whereas the pro-eutectoid cementite appears as a lighter phase. Atomic force microscopy (AFM) of etched steels is able to resolve ferrite and cementite lamellae in pearlite at similar magnifications. Both cementite in pearlite as well as pro-eutectoid cementite appear as raised areas (hills) in AFM images. Interlamellar spacing in pearlite increases with increasing hardenability of steel.

Experimental Study of EPS Decomposition in Lost Foam Casting Process

2001 ◽  
Author(s):  
Ying Liu ◽  
Sayavur I. Bakhtiyarov ◽  
Ruel A. Overfelt
Keyword(s):  
Differential Scanning Calorimetry ◽  
Heat Source ◽  
Casting Process ◽  
Expanded Polystyrene ◽  
Chamber Pressure ◽  
Neutral Atmosphere ◽  
Heating Rates ◽  
Scanning Calorimetry ◽  
Close Proximity ◽  
Foam Pattern

Abstract The thermal degradation of bulk and miniature samples of expanded polystyrene (EPS) has been investigated in a neutral atmosphere at 800°C and by differential scanning calorimetry over a range of temperatures. The differential scanning calorimetry experiments showed that the foam volatilization temperature is significantly affected by heating rate and varies from 380°C to 470°C at heating rates from 10–60°C/min. Bulk degradation due to the 800°C heat source appeared to occur instantly as the foam pattern approached the close proximity of the heat source. The chamber pressure increased and the heat source temperature dropped during degradation. The gas yield at 800°C was determined to be about 610 cm3 (STP)/g of EPS.

Expanded Polystyrene Spheres as Evaporation Suppressors

1980 ◽  
Vol 106 (3) ◽  
pp. 163-173
Author(s):  
Tariq A. Mahmoud ◽  
Natiq K. Bashi
Keyword(s):  
Expanded Polystyrene ◽  
Polystyrene Spheres
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