Toshiba Kikai Kabushiki Kaisha

Daido Steel Co., Ltd.

Kyoichi Sasaki

Yoshihisa Kato

Masaki Shimada

Naotaka Kawaguchi

A material for use in the production of an alloy having excellent corrosion resistance and abrasion resistance is provided. The material includes a cored wire formed from at least a pipe of matrix metal, which is at least one member selected from an Fe-base alloy, a Co-base alloy, and a Ni-base alloy. A VC powder having a particle diameter of 10 .mu.m or less is filled into the pipe. Also provided is a material for use in the production of an alloy having excellent corrosion resistance and abrasion resistance. The material includes a powder mixture containing at least a matrix metal, which is at least one member selected from an Fe-base alloy, a Co-based alloy and a Ni-base alloy, and a VC powder having a particle diameter of 10 .mu.m or less.

Alloy having excellent corrosion resistance and abrasion resistance,

A barrel for a twin screw extruder having a pair of helical screws has a barrel body provided with a pair of partly overlapping cylindrical bores, and the pair of helical screws are rotatably supported in the pair of cylindrical bores of the barrel to mix and extrude a molding material. An abrasion resistant layer is formed in at least portions of the surfaces of the pair of cylindrical bores extending in the vicinity of at least one of the two lines of intersection of the pair of partly overlapping cylindrical bores. The abrasion resistance of the abrasion resistant layer has a maximum in a portion thereof around the line of intersection of the pair of cylindrical bores and decreases gradually with distance from the line of intersection. The abrasion resistant layer is formed by depositing a material containing a hard substance by build-up welding, and the hard substance content of the material in the abrasion resistant layer is varied with distance from the line of intersection. The abrasion resistant layer is formed by depositing a material consisting of a corrosion resistant base alloy and a hard substance. The abrasion resistant layer may be formed on a corrosion resistant layer formed over the entire surfaces of the pair of cylindrical bores.

Barrel for a twin screw extruder with an abrasion resistant layer

Disclosed is a process for the preparation of an alloy having excellent corrosion resistance and wear resistance, which comprises subjecting a powdery mixture comprising a powder of at least one matrix metal selected from the group consisting of Fe-based alloys, Co-based alloys and Ni-based alloys and a vanadium carbide powder to a heat treatment, wherein by repeating fusion and re-fusion by a heat treatment using a heat source having a high energy density, a phase of uniform and fine vanadium carbide particles is recrystallized and/or redeposited in the matrix metal phase.

Process for preparation of corrosion-resistant and wear-resistant alloy

A process for preparing an alloy having excellent corrosion resistance and abrasion resistance is provided. The alloy is prepared by providing a powder mixture or VC-powder-containing wire having a matrix metal, including a VC powder having a particle diameter of 10 .mu.m or less, and at least one member selected from the group consisting of an Fe-base alloy, a Co-base alloy and a Ni-base alloy. The powder mixture or VC-powder-containing wire is melted with a heat source having a high energy density. The resultant melt is then cooled to homogeneously crystallize and/or precipitate VC, such that the particle diameter of the VC is reduced to 5 .mu.m or less in the matrix metal phase. Also disclosed is a process for preparing a surface-modified metallic member from a metallic member and an alloy prepared from the aforementioned process.

An alloy having excellent corrosion resistance and abrasion resistance, is provided comprising a matrix metal phase comprised of at least one member selected from an Fe-base alloy, a Co-base alloy and a Ni-base alloy and, present in the matrix metal phase, 10 to 65%, in terms of the area, of a substantially homogeneously crystallized and/or precipitated VC particle phase having a particle diameter of 5 .mu.m or less. A surface-modified metallic member, is also provided comprising a metallic member and the above-described alloy, the alloy being integrally coated on the surface of the metallic member at its desired portion.

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Numazu, Japan

Kyoichi Sasaki