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).

Examples of an alloy injection molded liquid metal substrate are described. In an example, an alloy injection molded liquid metal substrate includes a liquid metal substrate and an alloy injection molded on a first surface of the liquid metal substrate.

A valve body having a ring of dissimilar material and a method of forming the valve body are described. The valve body includes an inlet, an outlet and a ring of dissimilar material. The method includes forming a valve core, splitting the valve core, placing a metal ring of dissimilar material between two pieces of the valve core, casting a valve body around the valve core, and fusing the metal ring to the valve body.

A valve body having a ring of dissimilar material and a method of forming the valve body are described. The valve body includes an inlet, an outlet and a ring of dissimilar material. The method includes forming a valve core, splitting the valve core, placing a metal ring of dissimilar material between two pieces of the valve core, casting a valve body around the valve core, and fusing the metal ring to the valve body.

A method of manufacturing a valve body having one or more corrosion-resistant internal surfaces. The method involves performing a casting process, which includes pouring a first material into a mold box, to produce a valve body casting made of the first material. During the casting process, a layer of a second material is formed on one or more internal surfaces of the valve body casting, the second material having a higher corrosion resistance than the first material, by: (1) applying, with an additive manufacturing technique, the second material to one or more external surfaces of a core, and (2) inserting the core into the mold box. A portion of the first material binds to the second material on the one or more external surfaces of the core while the first material is poured into the mold box.

A method of manufacturing a valve body having one or more corrosion-resistant internal surfaces. The method involves performing a casting process, which includes pouring a first material into a mold box, to produce a valve body casting made of the first material. During the casting process, a layer of a second material is formed on one or more internal surfaces of the valve body casting, the second material having a higher corrosion resistance than the first material, by: (1) applying, with an additive manufacturing technique, the second material to one or more external surfaces of a core, and (2) inserting the core into the mold box. A portion of the first material binds to the second material on the one or more external surfaces of the core while the first material is poured into the mold box.

A composite roll for rolling having a structure comprising centrifugally cast outer and intermediate layers of an Fe-based alloy integrally fused to an inner layer of ductile cast iron; the outer layer having a composition comprising by mass 1-3% of C, 0.3-3% of Si, 0.1-3% of Mn, 0.5-5% of Ni, 1-7% of Cr, 2.2-8% of Mo, 4-7% of V, 0.005-0.15% of N, and 0.05-0.2% of B, the balance being Fe and inevitable impurities; the intermediate layer containing 0.025-0.15% by mass of B; the B content in the intermediate layer being 40-80% of that in the outer layer; and the total amount of Cr, Mo, V, Nb and W in the intermediate layer being 40-90% of that in the outer layer.

A composite roll for rolling having a structure comprising centrifugally cast outer and intermediate layers of an Fe-based alloy integrally fused to an inner layer of ductile cast iron; the outer layer having a composition comprising by mass 1-3% of C, 0.3-3% of Si, 0.1-3% of Mn, 0.5-5% of Ni, 1-7% of Cr, 2.2-8% of Mo, 4-7% of V, 0.005-0.15% of N, and 0.05-0.2% of B, the balance being Fe and inevitable impurities; the intermediate layer containing 0.025-0.15% by mass of B; the B content in the intermediate layer being 40-80% of that in the outer layer; and the total amount of Cr, Mo, V, Nb and W in the intermediate layer being 40-90% of that in the outer layer.

A construction machinery bucket part includes a body including a low alloy cast iron, and a wear resistant tip cast bonded to an end portion of the body and including a white cast iron. The construction machinery bucket part includes dissimilar materials, and has improved economic feasibility and wear resistance.

A process manufactures a metal part for a turbomachine that includes first and second metal materials with different chemical compositions. The process includes the steps of obtaining an element of which at least a first metallic part is made of the first metallic material and placing the element in a first mold and pouring wax into the mold to at least partially cover the element. The first mold has an impression corresponding to at least part of an external surface of the metal part. The process further includes obtaining an assembly by removing the first mold and making a shell mold with a first ceramic around the assembly. The process also includes removing the wax from the shell mold and pouring the second metal material into the shell mold in place of the wax, and removing any ceramics present in the assembly.