Nodular Cast Iron Rolls (ArMo)

TYPE ArMo	HARDNESS		CHEMICAL ANALYSIS						MECHANICAL PROPERTIES
TYPE ArMo	HB	ShC	C	Si	Mn	Cr	Ni	Mo	TENSILE STRENGHT (N/mm²)	BENDING STRENGHT (N/mm²)	MODULUS OF ELASTICITY (KN/mm²)
Ferritic - Pearlitic	300 ∻ 400	45 ∻ 58	2.90 ∻ 3.50	1.30 ∻ 2.00	0.30 ∻ 0.70	<= 0.30	1.70 ∻ 3.20	0.20 ∻ 0.50	~ 700	~ 1300	~ 180
Pearlitic	400 ∻ 550	58 ∻ 74	3.10 ∻ 3.60	0.90 ∻ 1.70	0.30 ∻ 1.00	0.10 ∻ 0.80	1.70 ∻ 3.20	0.20 ∻ 0.50	~ 500	~ 800	~ 180
Acicular	400 ∻ 555	58 ∻ 74	3.10 ∻ 3.60	0.80 ∻ 2.00	0.40 ∻ 1.00	<= 0.30	2.00 ∻ 4.00	0.40 ∻ 0.90	~ 600	~ 950	~ 180

Specifications

After being treated with Magnesium the graphite contained in spheroidal cast iron precipitates in the form of spheroids. Spheroidal cast iron has mechanical properties similar to cast steel whereas its wear resistance is typical of alloyes cast iron. Materials are subdivided on the basis of their matrix type as follows: ArMoT with a ferritic/pearlitic matrix, ArMoD with a pearlitic matrix, ArMoD-A with an acicular matrix. Mechanical properties, wear resistance and resistance to thermal fatigue depend on carbide and graphite ratio and on the typeof matrix.

Applications

ArMo rolls are used mainly in wire, rod, light, medium and heavy section mills. Particularly ArMoT type are used for roughing stands where high thermal stresses can take place; the ArMoD type for roughing and preparing stands and the ArMoD-A type for pre-finishing and finishing.