scholarly journals Chunky Graphite in Low and High Silicon Spheroidal Graphite Cast Irons–Occurrence, Control and Effect on Mechanical Properties

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5402
Author(s):  
Jon Sertucha ◽  
Garikoitz Artola ◽  
Urko de La Torre ◽  
Jacques Lacaze
Keyword(s):  
Mechanical Properties ◽  
Rare Earth ◽  
Rare Earths ◽  
Room Temperature ◽  
Spheroidal Graphite ◽  
Cast Irons ◽  
Charge Materials ◽  
Heavy Section ◽  
Chunky Graphite ◽  
High Silicon

Chunky graphite appears easily in heavy-section spheroidal graphite cast irons and is known to affect their mechanical properties. A dedicated experiment has been developed to study the effect of the most important chemical variables reported to change the amount of chunky graphite, namely the content in silicon and in rare earths. Quite unexpectedly, controlled rare earths contents appear beneficial for decreasing chunky graphite when using standard charge materials. Tin is shown to decrease chunky graphite appearance and it is evidenced that this effect is not related to rare earths. Finally, the effect of tin and antimony are compared and it is noticed that both suppress chunky graphite but also lead to some spiky graphite when no rare earth is added. Chunky graphite negatively affects the room temperature mechanical properties, though much more in the case of low silicon spheroidal graphite cast irons than in high silicon ones. Spiky graphite has been found to be much more detrimental and should thus be avoided.

scholarly journals Effect of Si and Ni Addition on Graphite Morphology in Heavy-Section Spheroidal Graphite Iron Parts

2018 ◽  
Vol 925 ◽  
pp. 70-77 ◽  
Author(s):  
Branko Bauer ◽  
Ivana Mihalic Pokopec ◽  
Mitja Petrič ◽  
Primož Mrvar
Keyword(s):  
Mechanical Properties ◽  
Cooling Rate ◽  
Metallographic Analysis ◽  
Spheroidal Graphite ◽  
Ni Content ◽  
Heavy Section ◽  
Graphite Morphology ◽  
Ni Addition ◽  
Chunky Graphite ◽  
Si Content

Metallographic analysis is applied to the study of the chunky graphite morphology in heavy-section castings of spheroidal graphite cast irons. Three castings with different Si and Ni content were prepared. Three positions in casting from the edge to the centre, with different cooling rates, were chosen for microstructure observation. The effect of the Si and Ni content on the graphite morphology and mechanical properties of heavy-section spheroidal graphite cast iron parts were investigated. Cerium containing commercial inoculant was used for in-stream inoculation. Chunky graphite area was estimated in micro-and macrostructure. Mechanical properties were determined on tensile test bars taken from the centre of the casting. Macro-and microstructure examination showed that the castings with high Si-content and Ni addition had chunky graphite present, while the castings produced by use of low Si and Ni containing charge had no chunky graphite. High Si-content is strong chunky graphite promoter, especially in castings with slow cooling rate. Ni addition also promotes chunky graphite formation, but only in thermal centre of the casting (where the cooling rate is the lowest). The elongation is severely lowered when chunky graphite appears in the microstructure.

Modification in Texture of Magnesium by the Addition of Rare Earth Elements and its Influence on Mechanical Properties

2012 ◽  
Vol 736 ◽  
pp. 307-315 ◽  
Author(s):  
Murugavel Suresh ◽  
Satyam Suwas
Keyword(s):  
Mechanical Properties ◽  
Rare Earth ◽  
Magnesium Alloys ◽  
Aluminium Alloys ◽  
Room Temperature ◽  
Main Obstacle ◽  
Rare Earth Addition ◽  
Structural Applications ◽  
Re Elements ◽  
The Relationship

Mg alloys show limited room temperature formability compared to its lightweight counterpart aluminium alloys, which is a main obstacle in using this metal for most of the structural applications. However, it is known that grain refinement and texture control are the two possibilities for the improvement of formability of magnesium alloys. Amongst the approaches attempted for the texture weakening, additions through of rare-earth (RE) elements have been found most effective. The relationship between the texture and ductility is well established. In this paper, the effect of rare earth addition on texture weakening has been summarized for various magnesium alloys under the two most common modes of deformation methods.

scholarly journals Thermal Analysis of the Formation of Chunky Graphite during Solidification of Heavy-section Spheroidal Graphite Iron Parts

2009 ◽  
Vol 49 (2) ◽  
pp. 220-228 ◽  
Author(s):  
Jon Sertucha ◽  
Ramón Suárez ◽  
Iker Asenjo ◽  
Peio Larrañaga ◽  
Jacques Lacaze ◽  
...  
Keyword(s):  
Thermal Analysis ◽  
Spheroidal Graphite ◽  
Spheroidal Graphite Iron ◽  
Heavy Section ◽  
Chunky Graphite

Influence of Ca-Ba and Sr Base Inoculants on Metallurgical and Mechanical Properties of Grey and Ductile Cast Irons

2018 ◽  
Author(s):  
Dhruv Patel ◽  
Devendra Parmar ◽  
Siddharthsinh Jadeja
Keyword(s):  
Mechanical Properties ◽  
Cast Iron ◽  
Uniform Distribution ◽  
Ductile Cast Iron ◽  
Grain Structure ◽  
Spheroidal Graphite ◽  
Primary Carbide ◽  
Cast Irons ◽  
Melt Temperature ◽  
Nodular Graphite

Microstructural adaptation of cast iron alloys by inoculation is a well-known practice to swell their mechanical properties. In foundries, several inoculants have been used to refine grain structure, and to obtain uniform distribution of graphite flakes. Inoculation is one of the most critical steps in cast iron production. The effectiveness of inoculants depends on melt temperature, method of addition, type of inoculants, and holding time. In this paper, the effect of Ca-based, Ba-based, Ca-Ba based and Sr-based inoculants on microstructure and tensile properties of grey cast iron IS-210 and spheroidal graphite iron IS-1862 is reported. Results showed both Ca and Ba based inoculants were effective in obtaining uniform distribution of flaky and nodular graphite in IS-210, and IS-1862 cast irons, respectively. But in a case of Sr-based inoculant were highly effective for increase the nodularity of SG cast iron as well as succeed supreme yield strength for both grey and ductile cast iron. The amounts of ferrite in the as-cast matrix are excess with controlled granulometry for elimination of primary carbide in Sr-based inoculant.

Effects of Nickel substitution by Manganese in Austenitic S.G. Cast Iron for Low-Temperature Uses

1984 ◽  
Vol 34 ◽  
Author(s):  
P. Poyet ◽  
P. Couchinave ◽  
P. I. Dancoisne
Keyword(s):  
Cast Iron ◽  
Low Temperature ◽  
Tensile Properties ◽  
Room Temperature ◽  
Manganese Content ◽  
Spheroidal Graphite ◽  
Cast Irons ◽  
Cast Material ◽  
Mechanical Tensile ◽  
High Level

ABSTRACTFor an economical purpose, an austenitic spheroidal graphite cast iron grade, containinq nickel-manganese, has been developed to replace Ni-Resist cast iron, type D2M, for cryogenic applications.Several tests were carried out to produce semi-industrial. heats of 200 kg so as to cast samples with a thickness ranging between 25 and 75 mm, and a variable nickel and manganese content. The resulting grades were compared each other and with Ni-Resist cast irons, before and after heat treatment, for their metallographic structure, their hardness, their mechanical tensile properties at room temperature and their impact values at temperatures down to - 150° C.The results show that it is possible to produce cast iron grades with 7 to 10 % manganese and 9 to 11 % nickel contents, featuring, at quenched state, better mechanical tensile properties at room temperature than Ni- Resist D2M with a 22–25 % Ni content, for roughly equivalent impact values at low temperatures. For as-cast material, the properties obtained vary with material thickness, and ductility is steeply decreasing for thicknesses under 30 mm.Weldability of Ni/Mn cast iron can be compared to Ni-Resist D2M weldability; machinability however seems more difficult, especially when boring quenched material.Generally speaking, the overall properties of these new grades and their lower cost-price if compared to Ni-Resist cast iron, should lead to promising outlets for low temperature uses and/or applications requiring high-level mechanical properties.

Effects of Rare Earth on the Inclusions and Mechanical Properties of Austenitic Stainless Steel

2013 ◽  
Vol 711 ◽  
pp. 99-102
Author(s):  
Xiao Liu ◽  
Jing Long Liang
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Rare Earth ◽  
Impact Toughness ◽  
Room Temperature ◽  
Transverse Impact ◽  
Dimple Fracture ◽  
Reduction Of Area ◽  
Room Temperature Strength

The effects of rare earth metals on the inclusions and the mechanical properties of 21Cr11Ni austenitic steel were studied by scanning electron microscope (SEM) and energy spectrum analysis. The results show that the morphologies and sizes of inclusions in 21Cr11Ni stainless steel are changed, and rare earth played a very good role of modifying inclusions. The fracture mode of 21Cr11Ni stainless steel is typical cleavage fracture, but quasi-cleavage and dimple fracture after adding RE into the steel. The transverse impact toughness of 21Cr11Ni stainless steel is improved obviously by RE. In comparison with 21Cr11Ni stainless steel without RE, the transverse impact toughness of 21Cr11Ni stainless steel with RE is increased 25.33% at-40°C, and the room temperature strength are improved, the elongation and reduction of area have been improved 9.18%, 12.71% respectively.

Effects of CeO2-Rich Mixed Rare Earth on the Mechanical Properties of Al2O3-Mullite Based Foam Ceramics

2010 ◽  
Vol 150-151 ◽  
pp. 815-820
Author(s):  
Shu Jun Ji ◽  
Xue Yi Guo ◽  
Jian Xiong Dong ◽  
Peng Su
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Rare Earth ◽  
Flexural Strength ◽  
Room Temperature ◽  
Strengthening Mechanism ◽  
Mechanism Analysis ◽  
Rare Earth Addition ◽  
The Matrix ◽  
Ceramic Microstructure

Using corundum, quartz, kaoline, etc, as base components and CeO2-rich mixed rare earth as modifier, foam ceramics were fabricated adopting the organic foam impregnation process. The mixed rare earth addition had much improving effects on the matrix mechanical properties owing to much glass phase and acerate mullite growing. While 3wt% was considered to be the optimal addition, in this case, homogeneous and compact ceramic microstructure with maximal glass condensation and minimal porosity formed, with the matrix compressive strength and the flexural strength at room temperature reached 0.87MPa and 0.66MPa respectively, which were 52.6% and 73.7% higher than the original samples respectively. As the mixed rare earth addition exceeded further, the compressive strength increased slowly and the flexural strength descended gradually. XRD and SEM were used to structure strengthening mechanism analysis.

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