There is provided a centrifugally cast composite roll for rolling having excellent wear resistance and surface deterioration resistance at levels of a high-speed steel cast iron roll and having rolling incident resistance at a level of a high alloy grain cast iron roll. A centrifugally cast composite roll for rolling having an outer layer and an inner layer, the outer layer including chemical components by mass ratio: C: 1.0 to 3.0%; Si: 0.3 to 3.0%; Mn: 0.1 to 3.0%; Ni: 0.1 to 6.0%; Cr: 0.5 to 6.0%; Mo: 0.5 to 6.0%; V: 3.0 to 7.0%; Nb: 0.1 to 3.0%; B: 0.001 to 0.1%; N: 0.005 to 0.070%; and the balance being Fe and inevitable impurities, wherein: the chemical composition of the outer layer satisfies following Formula (1), has a crystallization and precipitation amount of graphite suppressed to less than 0.3% by area ratio, and has 1 to 15% of MC carbide by area ratio; and the centrifugally cast composite roll for rolling does not have a cast defect having a diameter of ϕ4 mm or more at a boundary between the outer layer and the inner layer,

50×N+V<9.0  (1).

An iron-based alloy composition including: boron (B): 1. 6-2.4 wt. %; carbon (C): 2.2-3.0 wt. %; chromium (Cr): 3.5-5.0 wt. %; manganese (Mn): below 0.8 wt. %; molybdenum (Mo): 16.0-19.5 wt. %; nickel (Ni): 1.0-2.0 wt. %; silicon (Si): 0.2-2.0 wt. %; vanadium (V): 10.8-13.2 wt. %; and balanced with iron (Fe). Further, an item including a substrate portion and a hardfacing coating bonded to the substrate portion, wherein the hardfacing coating is made by an overlay welding process using the iron-based alloy composition.

There is provided a centrifugally cast composite roll for rolling having excellent wear resistance and surface deterioration resistance at levels of a high-speed steel cast iron roll and having rolling incident resistance at a level of a high alloy grain cast iron roll. Its outer layer includes chemical components by mass ratio: C: 1.5 to 3.5%; Si: 0.3 to 3.0%; Mn: 0.1 to 3.0%; Ni: 1.0 to 6.0%; Cr: 1.5 to 6.0%; Mo: 0.1 to 2.5%; V: 2.0 to 6.0%; Nb: 0.1 to 3.0%; B: 0.001 to 0.2%; N: 0.005 to 0.070%; and the balance being Fe and inevitable impurities, wherein: a chemical composition of the outer layer satisfies Formula (1) and has 5 to 30% of M.sub.3C carbide by area ratio; an outer layer Shore hardness (A) of a roll surface satisfies Formula (2); and a residual stress (B) of the roll surface satisfies Formula (3),

2×Ni+0.5×Cr+Mo>10.0  (1)

Hs 75≤A≤Hs 85  (2)

100 MPa≤B≤350 MPa  (3).

Provided is a black heart malleable cast iron and a method for manufacturing the same which can significantly shorten the time required for graphitization, as compared with the prior art. The black heart malleable cast iron includes a matrix of ferrite and lump graphite included in the matrix, and includes at least one selected from the group consisting of (i) 0.0050% by mass or more and 0.15% by mass or less of bismuth and 0.020% by mass or more of manganese, and (ii) 0.0050% by mass or more and 1.0% by mass or less of aluminum and 0.0050% by mass or more of nitrogen. In addition, the grain size of the matrix is 8.0 or more and 10.0 or less in terms of grain size number, numerically determined by comparison between a metallographic photograph of the matrix and a standard grain size chart.

A cylinder liner of the present invention is a cylinder liner mounted on a cylinder block and formed of flaky graphite cast iron, at least a nitrided layer is provided on an inner periphery of the cylinder liner, and a cross hatching section is formed on the inner periphery, a roughness curve of the inner periphery has a plateau honing shape, a ten-point average roughness Rz of the inner periphery pursuant to JIS B0601:1982 is 4.0 μm or less, and an average value of an area ratio of pits generated in the inner periphery is 8% or less.

A cylinder liner of the present invention is a cylinder liner mounted on a cylinder block and formed of flaky graphite cast iron, at least a nitrided layer is provided on an inner periphery of the cylinder liner, and a cross hatching section is formed on the inner periphery, a roughness curve of the inner periphery has a plateau honing shape, a ten-point average roughness Rz of the inner periphery pursuant to JIS B0601:1982 is 4.0 μm or less, and an average value of an area ratio of pits generated in the inner periphery is 8% or less.

A method is disclosed for producing a brake element, in particular a brake disk or brake drum, which has a friction portion and a fastening portion, wherein a blank for at least the friction portion is produced by a casting method from gray cast iron with lamellar graphite, wherein the blank is subjected to austenitizing at a predefined austenitizing temperature, and wherein the austenitized blank is subjected to austempering at a predefined austempering temperature. The friction portion and the fastening portion is produced in one piece, and that the fastening portion is produced with a wall thickness of at least 1.5 and at most 4.5 mm.

A method is disclosed for producing a brake element, in particular a brake disk or brake drum, which has a friction portion and a fastening portion, wherein a blank for at least the friction portion is produced by a casting method from gray cast iron with lamellar graphite, wherein the blank is subjected to austenitizing at a predefined austenitizing temperature, and wherein the austenitized blank is subjected to austempering at a predefined austempering temperature. The friction portion and the fastening portion is produced in one piece, and that the fastening portion is produced with a wall thickness of at least 1.5 and at most 4.5 mm.

A cast for producing end plates for a pump assembly, the cast comprising a base portion and a pair of projections, the pair of projections providing material to machine bearing assembly housings for accommodating drive and idler shafts in the pump assembly. Also provided is an inner plate bushing for an end plate in a pump assembly, the inner plate bushing comprising a collar extending from a flange, the collar to be inserted into a mounting recess in the end plate with the flange seating flush with a surface of the end plate, the surface area of an end of the collar being larger than an inner surface of the flange.

The present invention suppresses leakage of combustion gas from a contact surface. A cylinder head (20) is attached to a cylinder block. The surface (26) of the side of the cylinder head (20) that is attached to the cylinder block includes a first region (AH1) and a second region (AH2) that has higher hardness than the first region (AH1).