Shell Like Fractures in Continuously Cast Slabs

Mišičko, Rudolf; Fedáková, Sandra Ahmidat; Vojtko, Marek

doi:10.12776/amsc.v3i0.119

Cited by 2 publications

(2 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These intercrystalline facets were observed in samples at the lowest slab pulling rate 0.43m.min -1 . The occurrence of intercrystalline facets along austenite grain boundaries indicates a decrease in mechanical properties, especially plasticity [10][11][12][13]. Transition slab No.1 at both lower pulling rates showed the presence of clusters of inclusions in the surface area.…”

Section: Discussionmentioning

confidence: 99%

Influence of Casting Rate on TiNb Microalloyed Steel Slab Surface Area Microstructure

Bekeč

Longauerová

Vojtko

2014

MSF

View full text Add to dashboard Cite

Two slabs of Ti-Nb microalloyed steel were analysed in this work. The first slab was transitional with the initial pulling rate 0.43 m.min-1 and the final pulling rate 0.9 m.min-1. The second slab was cast at the real production pulling rate 1.03 m.min-1. The presence of larger amounts of oscillation marks was observed on the first slab at both pulling rates. The second slab showed no oscillation marks. At the lowest pulling rate, cracks were discovered below the slab surface, often below oscillation marks. Cracks were seldom observed at pulling rate 0.9 m.min-1. In the first slab, especially at the low pulling rate, the presence of cracks and pores was found. Pores were observed often with clusters of aluminum oxides. The microstructure of the slab surface zone was characterised by heterogeneity of ferrite grain sizes at all three pulling rates. This heterogeneity was manifested mainly in the marginal cut-outs at all pulling rates. In the marginal cut-outs the microstructure was granulometrically finer at all three pulling rates than in the central cut-outs. Non-equilibrium microstructure in the marginal cut-outs was also observed.

show abstract

Section: Discussionmentioning

confidence: 99%

Influence of Casting Rate on TiNb Microalloyed Steel Slab Surface Area Microstructure

Bekeč

Longauerová

Vojtko

2014

MSF

View full text Add to dashboard Cite

show abstract

“…However, slag entrapments, inclusions, and/or other metallurgical penetrators are not the only causes of metallurgical defects. Operating parameters impeding homogeneous solidification during casting such as high superheat, improper casting speed in continuous casting machine (CCM), supporting rolls misalignment, and inadequate and inhomogeneous cooling distribution can enhance micro-and macro-segregation (centerline segregation) and within the as-cast structure leading to internal and surface defects (Le Papillon et al, 2002;Mišičko et al, 2013;ASM Handbook, 2000;Schwerdtfeger and Senk, 2010). Hot tears, bleeds comprise typical defects of semi-finished products (slabs and blooms) that lead to high-temperature oxidized cracks adjacent to localized decarburized ferritic zone during reheating, found overlapped in a sliver-like form in the final plates and bars products, respectively.…”

Section: Appearance Of Defects During Industrial Productionmentioning

confidence: 99%

Typical defects in plate and long steel products

Papaefthymiou

Tzevelekou²,

Αντωνόπουλος³

et al. 2016

Int Jnl of Struct Integrity

View full text Add to dashboard Cite

Purpose -During steel plate and long-product production, numerous imperfections and defects appear that deteriorate product quality and consequently reduce revenue. The purpose of this paper is to provide a practical overview of typical defects (surface and internal) that occur and their root causes. Design/methodology/approach -The data presented here derive from the quality department and from more than 50 technical reports of ELKEME S.A. on the last decade's production of steel making companies STOMANA S.A. and SIDENOR S.A., with emphasis on the defects occurred in some of the products of the Bulgarian plant. Stereoscopic observations of surface defects, light optical metallography, and scanning electron microscopy with EDS represent the most used techniques to characterize defected macro-/micro-areas and microstructures. Findings -In general, the most commonly encountered defects from semi-finished (billets, blooms, and slabs) and final (round bar and plate) steel products are as follows: network cracks, porosity, gas holes, shrinkage, shell, slivers, casting powder entrapment, ladle slag entrapment, other non-metallic inclusions, low hot ductility, centerline segregation cracking, macro-and micro-segregation, and mechanical defects (scratches, transverse cracks, and seams). Practical implications -External and internal quality improvement can reduce the production cost (Euro/ton). Social implications -Improvement of the quality of industrial plates and long products increases the safety of the further-produced constructions and systems such as bridges, cranes, heavy equipment, automobile parts, etc. Originality/value -Root cause analysis and categorization of the most commonly encountered defects can pave the way to production process improvements that directly affect final product quality and the overall per ton production cost. The benefits of this work obviously affect all steel producers/ processers, and also society through the safety increase achieved by the quality improvement in the steel products used in constructions and automobile parts.

show abstract

Shell Like Fractures in Continuously Cast Slabs

Cited by 2 publications

References 1 publication

Influence of Casting Rate on TiNb Microalloyed Steel Slab Surface Area Microstructure

Influence of Casting Rate on TiNb Microalloyed Steel Slab Surface Area Microstructure

Typical defects in plate and long steel products

Contact Info

Product

Resources

About