scholarly journals Improvement in the Resistance to Wear of Work-Rolls Used in Finishing Stands of the Hot Strip Mills

Metals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1873
Author(s):  
Alberto Cofiño-Villar ◽  
Florentino Alvarez-Antolin ◽  
Carlos Hugo Alvarez-Perez
Keyword(s):  
Cast Iron ◽  
White Cast Iron ◽  
Outer Zone ◽  
Spheroidal Graphite ◽  
Hot Strip ◽  
Eutectic Constituent ◽  
Grey Cast ◽  
Resistance To Wear ◽  
Hot Strip Mills ◽  
Work Rolls

Work-rolls manufactured through the Indefinite Chill Double Poured (ICDP) method present an exterior work layer manufactured in a martensitic white cast iron alloyed with 4.5 %Ni, 1.7 %Cr, and 0.7 %Nb (wt.%). In its microstructure, there are abundant carbides of the type M3C and MC, which give high resistance to wear, and graphite particles which improve the service behaviour of the rolls against thermal cycling. The core of the rolls is manufactured in grey cast iron of pearlitic matrix and spheroidal graphite. These work-rolls are used in the finishing stands in Hot Strip Mills for rolling slabs proceeding from continuous casting at 1200 °C. Through the application of a Design of Experiments (DoE), an attempt has been made to identify those manufacturing factors which have a significant effect on resistance to wear of these rolls and to find an optimal combination of levels of these factors which allow for improvement in resistance to wear. To increase resistance to wear, it is recommended to situate, simultaneously, the liquidus temperature and the percentage of Si in the respective ranges of 1250–1255 °C and 1.1–1.15 (wt.%). Higher liquidus temperatures favour the presence of the pro-eutectic constituent rather than the eutectic constituent. The outer zone of the work layer, in contact with the metal sheet, which is being rolled, does not show the graphitising effect of Si (0.8–1.15 wt.%). On the contrary, it confirms the hardening effect of the Si in solid solution of the ferrite. The addition of 0.02% of Mg (wt.%) and the inoculation of 6 kg/T of FeB tend to eliminate the graphitising effect of the Si, thus favouring that the undissolved carbon in the austenite is found to form carbides in contrast to the majority formation of graphite.

scholarly journals Enhancement of the Quality of the Shell-Core Bond Interface in Duplex Work Rolls Manufactured by Centrifugal Casting Used in Hot Strip Mills

Materials ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1304 ◽  
Author(s):  
Alberto Cofiño-Villar ◽  
Florentino Alvarez-Antolin ◽  
Juan Asensio-Lozano
Keyword(s):  
Cast Iron ◽  
Impact Toughness ◽  
Centrifugal Casting ◽  
Complete Fusion ◽  
The Core ◽  
Hot Strip ◽  
Bond Interface ◽  
Hot Strip Mills ◽  
The Impact ◽  
Work Rolls

To ensure the formation of a sound shell-core bond interface free of defects between the shell and the core in work rolls used in the finishing stands of hot strip mills, a complete fusion of this interface must be achieved, avoiding excessive mixing of the two components and the formation of hard, fragile microstructures. The shell is made of white cast iron, alloyed with Ni and Cr, and the core is manufactured of grey cast iron spheroidal graphite in a pearlitic matrix. It is thus advisable to inoculate the shell with 0.6 kg/T SiCaMn, as this promotes discontinuity in the carbide network and leads to an increase in the impact toughness of the bond interface. Furthermore, inoculation of the shell with FeSi-La should be avoided, as this inoculant leads to an increase in graphite counts, promoting it with a lamellar morphology at the edge of the bond and hence reducing the impact toughness in this interface. Addition of Mg to the shell has been found to produce an increase in hardness in the regions adjacent to the bond interface.

scholarly journals Effect of MC Type Carbides on Wear Resistance of High Wear Resistant Cast Iron Rolls Developed for Work Rolls of Hot Strip Mills

2020 ◽  
Vol 106 (12) ◽  
pp. 883-891
Author(s):  
Kazunori Kamimiyada ◽  
Shinya Ishikawa ◽  
Hirofumi Miyahara ◽  
Yuji Konno
Keyword(s):  
Wear Resistance ◽  
Cast Iron ◽  
Wear Resistant ◽  
Hot Strip ◽  
Hot Strip Mills ◽  
Work Rolls

Thermal stresses in the work rolls of hot-strip mills

Metallurgist ◽  
2009 ◽  
Vol 53 (9-10) ◽  
pp. 560-564
Author(s):  
L. S. Kokhan ◽  
A. V. Aldunin ◽  
N. A. Farunda ◽  
L. M. Semenova
Keyword(s):  
Thermal Stresses ◽  
Hot Strip ◽  
Hot Strip Mills ◽  
Work Rolls

scholarly journals Preparation and Microstructural Characterization of a High-Cr White Cast Iron Reinforced with WC Particles

Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2596
Author(s):  
Aida B. Moreira ◽  
Laura M. M. Ribeiro ◽  
Pedro Lacerda ◽  
Ricardo O. Sousa ◽  
Ana M. P. Pinto ◽  
...  
Keyword(s):  
Cast Iron ◽  
Base Metal ◽  
White Cast Iron ◽  
Microstructural Characterization ◽  
Ex Situ ◽  
Matrix Composites ◽  
The Matrix ◽  
Eutectic Constituent ◽  
Cold Pressed

High-chromium white cast iron (WCI) specimens locally reinforced with WC–metal matrix composites were produced via an ex situ technique: powder mixtures of WC and Fe cold-pressed in a pre-form were inserted in the mold cavity before pouring the base metal. The microstructure of the resulting reinforcement is a matrix of martensite (α’) and austenite (γ) with WC particles evenly distributed and (Fe,W,Cr)6C carbides that are formed from the reaction between the molten metal and the inserted pre-form. The (Fe,W,Cr)6C precipitation leads to the hypoeutectic solidification of the matrix and the final microstructure consists of martensite, formed from primary austenite during cooling and eutectic constituent with (Fe,Cr)7C3 and (Fe,W,Cr)6C carbides. The presence of a reaction zone with 200 µm of thickness, between the base metal and the composite should guarantee a strong bonding between these two zones.

Work Rolls in Hot Strip Mills

1971 ◽  
Vol 57 (5) ◽  
pp. 761-772 ◽  
Author(s):  
Hidemaro KAWAHARA
Keyword(s):  
Hot Strip ◽  
Hot Strip Mills ◽  
Work Rolls

NI-HARD

Alloy Digest ◽  
1954 ◽  
Vol 3 (11) ◽  
Keyword(s):  
Cast Iron ◽  
Physical Properties ◽  
White Cast Iron ◽  
Nickel Content ◽  
High Hardness ◽  
Heat Treating ◽  
White Iron ◽  
Grey Cast ◽  
Carbide Matrix ◽  
Heavy Castings

Abstract NI-HARD is a white cast iron alloyed with nickel and chromium to give high hardness and outstanding resistance to abrasion. The structure consists of hard carbide matrix rendered martensitic by the nickel content. The wearing faces of heavy castings may be chilled, thus giving a white iron face, backed by grey cast iron where the metal has cooled more slowly. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on casting, heat treating, machining, and joining. Filing Code: CI-9. Producer or source: Allen-Sherman-Hoff Pump Company.

Experimental Investigation of Twist Fatigue Characteristics on Piston Rings

2020 ◽  
Vol 12 (2) ◽  
Author(s):  
E. Pavithra ◽  
Mahesh Dhakal ◽  
Prithvi Hada ◽  
N. Yuvaraj ◽  
K. Sridhar
Keyword(s):  
Cast Iron ◽  
Internal Combustion Engines ◽  
Piston Ring ◽  
Spheroidal Graphite ◽  
Piston Rings ◽  
Cast Irons ◽  
Spheroidal Graphite Cast Iron ◽  
Graphite Cast Iron ◽  
Grey Cast ◽  
Fatigue Characteristics

Piston ring is one of the most important parts of the internal combustion engines. This paper investigates the mechanical and twist fatigue characteristics on different piston ring materials. The piston ring materials were chosen in this study such as grey cast irons (3740 and 6140), malleable cast iron (3929), spheroidal graphite cast iron (6139) and martensitic carbidic grey cast iron (6454). Twist fatigue test was conducted on different materials of piston rings in order to identify the suitable piston ring for the effective operation. Geometrical features and the mechanical properties were also assessed in different materials for the effectiveness of piston rings.

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