The high Cr content of the shell material and the absence of free graphite characterize these grades. Different types of carbides with high hardness and a tempered martensitic microstructure guarantee an excellent wear resistance. All high chromium rolls are high temperature heat treated and tempered to obtain optimal properties.

They bring high performance figures in the first finishing stands of Hot Strip Mills, Skin Pass stands and in finishing stands of small sect ion mills.

These rolls have hardly any hardness drop in the shell. The core can be made of nodular or lamellar graphite iron. This grade due to lack of graphite in the shell is sensitive to fire cracks and require mills with well designed cooling system.

Enhanced Hi Cr rolls are alloyed additionally with W, V and Nb to increase the hardness of eutectic carbides, hence increasing the performance of the rolls significantly.

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CrH76C-Tempered Martensite with

   Eutectic and Secondary Carbide(x100)

CrH76C-Tempered Martensite with

 Eutectic and Secondary Carbide(x500)

 

Roll

Grade

Barrels

Hardness

(ShC)

C

(%)

Si

(%)

Mn

(%)

Cr

(%)

Ni

(%)

Mo

(%)

V+Nb

(%)

Composition Hardness

 and Mechanical

 Properties of Core

Material

Cr H 72 C

72

2.5-3.2

0.3-0.8

0.7-1.6

16.0-22.0

1.0-2.5

1.0-2.5

See core Material Info in link1

Cr H 76 C

76

2.5-3.2

0.3-0.8

0.7-1.6

16.0-22.0

1.0-2.5

1.0-2.5

See core Material Info in link1

Cr H 78 C

78

2.5-3.2

0.3-0.8

0.7-1.6

16.0-22.0

1.0-2.5

1.0-2.5

See core Material Info in link1

Cr H 80 C

80

2.5-3.2

0.3-0.8

0.7-1.6

16.0-22.0

1.0-2.5

1.0-2.5

See core Material Info in link1

Cr H 84 C

84

2.5-3.2

0.3-0.8

0.7-1.6

16.0-22.0

1.0-2.5

1.0-2.5

See core Material Info in link1

CrA H 72 C

72

2.5-3.2

0.3-0.8

0.7-1.6

16.0-22.0

1.0-2.5

1.0-2.5

See core Material Info in link1

CrA H 76 C

76

2.5-3.2

0.3-0.8

0.7-1.6

16.0-22.0

1.0-2.5

1.0-2.5

0.2-1.5

See core Material Info in link1

CrA H 78 C

78

2.5-3.2

0.3-0.8

0.7-1.6

16.0-22.0

1.0-2.5

1.0-2.5

0.2-1.5

See core Material Info in link1

CrA H 80 C

80

2.5-3.2

0.3-0.8

0.7-1.6

16.0-22.0

1.0-2.5

1.0-2.5

0.2-1.5

See core Material Info in link1

CrA H 84 C

84

2.5-3.2

0.3-0.8

0.7-1.6

16.0-22.0

1.0-2.5

1.0-2.5

0.2-1.5

See core Material Info in link1

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Note: On request, other roll grades not specified in the table can be produced. Cores for compound rolls can be produced on request with Grey, Compact or Nodular cast iron.