A powder composition is used for the fabrication of casting inserts, designed to produPce local composite zones resistant to abrasive wear. The composite zones are reinforced with carbides and borides or with mixtures thereof formed in situ in castings. The powder includes powder reactants of the formation of carbides and/or borides selected from the group of TiC, WC, ZrC, NbC, TaC, TiB.sub.2, ZrB.sub.2, or mixtures thereof. The carbides and/or borides forming after crystallization particles reinforces the composite zones in castings. The powder composition further includes moderator powders in the form of a mixture of metal powders, which after crystallization form matrix of the composite zone in casting. A casting insert is disclosed for the fabrication in casting of local composite zones resistant to abrasive wear. A method for the fabrication of local composite zones in castings uses for this purpose the reaction of the self-propagating high temperature synthesis (SHS).

A powder composition is used for the fabrication of casting inserts, designed to produPce local composite zones resistant to abrasive wear. The composite zones are reinforced with carbides and borides or with mixtures thereof formed in situ in castings. The powder includes powder reactants of the formation of carbides and/or borides selected from the group of TiC, WC, ZrC, NbC, TaC, TiB.sub.2, ZrB.sub.2, or mixtures thereof. The carbides and/or borides forming after crystallization particles reinforces the composite zones in castings. The powder composition further includes moderator powders in the form of a mixture of metal powders, which after crystallization form matrix of the composite zone in casting. A casting insert is disclosed for the fabrication in casting of local composite zones resistant to abrasive wear. A method for the fabrication of local composite zones in castings uses for this purpose the reaction of the self-propagating high temperature synthesis (SHS).

A coating liquid for preparing a needle-shaped cylinder liner, comprising the following components: 0.05-0.4 parts of an anionic surfactant; 0.05-0.5 parts of tannic acid; 0.15-0.7 parts of caustic soda; 22-38 parts of diatomite; 3-10 parts of montmorillonite; and 62-75 parts of water. A method for preparing a needle-shaped cylinder liner comprises spraying a coating liquid for preparing the needle-shaped cylinder liner onto the inner wall of a hollow cylindrical mould, and drying the coating liquid to obtain a mould with a coating attached to the surface of the inner wall; adding an inoculated iron liquid into the rotary mould, and cooling and demoulding to obtain a cylinder liner blank; and subjecting the blank to outer surface cleaning and forming machining to obtain the needle-shaped cylinder liner.

A coating liquid for preparing a needle-shaped cylinder liner, comprising the following components: 0.05-0.4 parts of an anionic surfactant; 0.05-0.5 parts of tannic acid; 0.15-0.7 parts of caustic soda; 22-38 parts of diatomite; 3-10 parts of montmorillonite; and 62-75 parts of water. A method for preparing a needle-shaped cylinder liner comprises spraying a coating liquid for preparing the needle-shaped cylinder liner onto the inner wall of a hollow cylindrical mould, and drying the coating liquid to obtain a mould with a coating attached to the surface of the inner wall; adding an inoculated iron liquid into the rotary mould, and cooling and demoulding to obtain a cylinder liner blank; and subjecting the blank to outer surface cleaning and forming machining to obtain the needle-shaped cylinder liner.

A composite roll for rolling comprising an outer layer and an inner layer integrally fused to each other; the outer layer being made of an Fe-based alloy comprising by mass 1-3% of C, 0.3-3% of Si, 0.1-3% of Mn, 0.1-5% of Ni, 1-7% of Cr, 1-8% of Mo, 4-7% of V, 0.005-0.15% of N, and 0.05-0.2% of B; the inner layer being made of graphite cast iron comprising by mass 2.4-3.6% of C, 1.5-3.5% of Si, 0.1-2% of Mn, 0.1-2% of Ni, less than 0.7% of Cr, less than 0.7% of Mo, 0.05-1% of V, and 0.01-0.1% of Mg; the inner layer comprising a core portion fused to the outer layer, and shaft portions integrally extending from both ends of the core portion; at least one of the shaft portions containing 200/cm.sup.2 or more of hard MC carbides having circle-equivalent diameters of 5 μm or more.

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).

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).

The coupler system of a railway car truck is constructed such that basic overall appearance may be maintained, but the actual material of which it is constructed is changed. According to one embodiment, the coupler is constructed from cast austempered ductile iron; whereas cast iron has a density, 0.26 lbs/in{circumflex over ( )}3, which is approximately 8% less than steel, 0.283 lbs/in{circumflex over ( )}3, thereby allowing for a reduction in weight over steel. A suitable austempering process is used to produce the austempered metal coupler and components thereof. A second benefit of embodiments of the present invention provides for a more efficient use of materials, meaning less metal is used to make the same final shape, as a way of reducing the coupler weight. Both factures combined allow for a lighter weight coupler, while utilizing the standard designs. Alternate coupler configurations are disclosed for further reducing coupler weight.

Lightweight yokes are provided. According to some embodiments, the basic overall appearance of the yoke may be maintained, but the actual material of which it is constructed is changed. According to other embodiments, the yoke is provided with an improved lightweight construction, and, yet other embodiments the yoke may be provided with an improved construction and formed from a preferred material. Yokes may be constructed from cast austempered ductile iron; whereas cast iron has a density, 0.26 lbs/in{circumflex over ( )}3, which is approximately 8% less than steel, 0.283 lbs/in{circumflex over ( )}3, thereby allowing for a reduction in weight over steel. A suitable austempering process is used to produce the austempered metal yoke. Yokes have improved configurations which may require less metal to produce the yoke. Both, the lightweight material and improvements in configuration of the yoke structure may combine to provide a lighter weight yoke.

Lightweight yokes are provided. According to some embodiments, the basic overall appearance of the yoke may be maintained, but the actual material of which it is constructed is changed. According to other embodiments, the yoke is provided with an improved lightweight construction, and, yet other embodiments the yoke may be provided with an improved construction and formed from a preferred material. Yokes may be constructed from cast austempered ductile iron; whereas cast iron has a density, 0.26 lbs/in{circumflex over ( )}3, which is approximately 8% less than steel, 0.283 lbs/in{circumflex over ( )}3, thereby allowing for a reduction in weight over steel. A suitable austempering process is used to produce the austempered metal yoke. Yokes have improved configurations which may require less metal to produce the yoke. Both, the lightweight material and improvements in configuration of the yoke structure may combine to provide a lighter weight yoke.