Microscopic Characterization of Different Shrinkage Defects in Ductile Irons and their Relation with Composition and Inoculation Process

Regordosa, Anna; Llorca-Isern, Núria

doi:10.1007/s40962-016-0120-9

Cited by 18 publications

(9 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…2), the lower is the inoculation the lower would be the risk of shrinkage formation. This conclusion is not contradictory with previous reports showing the beneficial effect of inoculation in decreasing shrinkage [4,8] as it should be pointed out that these earlier works compared inoculated to non-inoculated alloys. The present results show that inoculation is expected to decrease shrinkage tendency whereas over-inoculation appears to be detrimental.…”

Section: Resultssupporting

confidence: 58%

“…Regordosa and Llorca-Isern [4] reported that shrinkage porosity obtained in hypoeutectic and hypereutectic inoculated alloys differs in extent and characteristics. Pipe (open macroshrinkage), caved surfaces and internal macroshrinkage were detected in case of hypoeutectic alloys while only internal macroshrinkage with smaller size was present in hypereutectic alloys.…”

Section: Discussionmentioning

confidence: 98%

“…The area of this porosity was finally measured using an image analysis software. Full experimental details about this second series have been reported elsewhere [4]. Composition ranges of cast alloys for all significant elements are shown in Table 2 where C refers to carbon content determined by combustion and the contribution of inoculation to silicon contents has been considered.…”

Section: Methodsmentioning

confidence: 99%

See 2 more Smart Citations

Evolution of Shrinkage with Carbon Equivalent and Inoculation in Ductile Cast Irons

Regordosa

Llorca-Isern

Sertucha

et al. 2018

MSF

Self Cite

View full text Add to dashboard Cite

Studying how shrinkage porosity changes size when varying the composition of ductile irons is still of interest for manufacturing sound cast parts and defining optimised processing conditions. Usual changes in carbon and silicon contents strongly affect shrinkage, so that a detailed analysis of the effect of alloy composition and of inoculation level on porosity was carried out in the present study. Two test castings have been used to evaluate the extent of porosity formed using different compositions and inoculation levels. It has been observed that increasing carbon content from hypoeutectic to near-eutectic compositions reduces the amount of defects while a further increase of shrinkage porosity is detected for hypereutectic compositions. Thus, a minimum in shrinkage tendency exists for slightly hypereutectic compositions. Although inoculation decreases shrinkage, the relevance of this parameter varies as a function of carbon equivalent.

show abstract

Section: Resultssupporting

confidence: 58%

Section: Discussionmentioning

confidence: 98%

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Evolution of Shrinkage with Carbon Equivalent and Inoculation in Ductile Cast Irons

Regordosa

Llorca-Isern

Sertucha

et al. 2018

MSF

Self Cite

View full text Add to dashboard Cite

show abstract

“…Many research and foundry experiments were performed to find the most important influencing factors favourable for shrinkage and micro-shrinkage formation to avoid this frequent defect in metal castings production. In this respect, different factors were identified, such as the chemistry of a treated cast iron (Compositional factor -C+1/7Si, Mg res , minor elements), mold features (rigidity/deformability, hardness stability), casting geometry (section modulus, feeding path), charge and melting practice (steel scrap/pig iron ratio, superheating level), pouring temperature, and inoculation treatment (type and amount of inoculant, nodule count) [13][14][15][16][17][18][19][20][21][22] .…”

Section: Special Reviewmentioning

confidence: 99%

Simultaneous thermal and contraction / expansion curves analysis for solidification control of cast irons

et al. 2020

View full text Add to dashboard Cite

T he final control of the iron castings' quality involves different techniques, including chemical analysis, microstructure evaluation, physical and mechanical properties measurements, castings' surface parameters and casting soundness control, etc. It is important to forecast the final castings' characteristics before mould filling, by iron melt solidification control, applying techniques able to illustrate the eutectic undercooling values referring to the stable and metastable equilibrium temperatures, carbide or graphite formation tendency, a specific graphite morphology occurrence, metal matrix make-up, shrinkage and microshrinkage sensitivity, etc.Thermal (cooling curve) analysis has a wide application in the worldwide foundry industry to quickly control the solidification behaviour of foundry metallic alloys, especially for cast irons and non-ferrous alloys. At first, cooling curve analysis (CCA) *Iulian RiposanBorn in 1948, Ph.D, Professor. His research interests mainly focus on processing and complex characterization of lamellar, nodular, compacted/vermicular and coral graphite irons, austempered cast irons with lamellar, nodular, compacted or coral graphite, cast iron matrix composites, cupola and electric furnaces operations. To date, he has published more than 300 technical papers and 3 technical books, and holds 35 patents. He is the honorary member of Technical Sciences Academy of Romania, the Past President of Romanian Foundry Technical Association (ATTR) (1996 -2014), and an international member of American Foundry Society.

show abstract

“…All these defects can be only partly avoided through the optimization of the production process. For example, it was found that adjusted post-inoculation could decrease the dimensions of microshrinkage porosities in heavy section castings [9,10].…”

Section: Introductionmentioning

confidence: 99%

Effect of Solidification Time on Microstructural, Mechanical and Fatigue Properties of Solution Strengthened Ferritic Ductile Iron

Borsato

Ferro

Berto

et al. 2018

Metals

View full text Add to dashboard Cite

Microstructural, mechanical, and fatigue properties of solution strengthened ferritic ductile iron have been evaluated as functions of different solidification times. Three types of cast samples with increasing thickness have been produced in a green sand automatic molding line. Microstructural analyses have been performed in order to evaluate the graphite nodules parameter and matrix structure. Tensile and fatigue tests have been carried out using specimens taken from specific zones, with increasing solidification time, inside each cast sample. Finally, the fatigue fracture surfaces have been observed using a scanning electron microscope (SEM). The results showed that solidification time has a significant effect on the microstructure and mechanical properties of solution strengthened ferritic ductile iron. In particular, it has been found that with increasing solidification times, the microstructure becomes coarser and the presence of defects increases. Moreover, the lower the cooling rate, the lower the tensile and fatigue properties measured. Since in an overall casting geometry, same thicknesses may be characterized by different microstructures and mechanical properties induced by different solidification times, it is thought that the proposed methodology will be useful in the future to estimate the fatigue strength of cast iron castings through the numerical calculation of the solidification time.

show abstract

Microscopic Characterization of Different Shrinkage Defects in Ductile Irons and their Relation with Composition and Inoculation Process

Cited by 18 publications

References 8 publications

Evolution of Shrinkage with Carbon Equivalent and Inoculation in Ductile Cast Irons

Evolution of Shrinkage with Carbon Equivalent and Inoculation in Ductile Cast Irons

Simultaneous thermal and contraction / expansion curves analysis for solidification control of cast irons

Effect of Solidification Time on Microstructural, Mechanical and Fatigue Properties of Solution Strengthened Ferritic Ductile Iron

Contact Info

Product

Resources

About