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 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.

Provided is a hot-working tool capable of maintaining adequate toughness even if the permissible amount of P contained in the hot-working tool is increased. The present invention is a hot-working tool, which has a component composition that can be adjusted to a martensitic structure by quenching and has a post-quenching and tempering martensitic structure, wherein: the component composition comprises greater than 0.020 mass % to 0.050 mass % of P; prior austenite grain diameter in said post-quenching and tempering martensitic structure is at least No. 9.5 in grain size number according to JIS-G-0551; and the P concentration of the grain boundary of said prior austenite particles is not more than 1.5 mass %. A hot-working tool wherein said component composition also comprises not more than 0.0250 mass % of Zn is preferable. The present invention also is a method for manufacturing a hot-working tool in which quenching and tempering are performed on a hot-working tool material with said component composition.

A martensitic stainless steel containing, by mass %, C: 0.20% to 0.40%, N: 0.1% or less, Mo: 3% or less, and Cr: 12.0% to 16.0%, such that 0.3%C+N0.4% and a PI value (=Cr+3.3Mo+16N) is 18 or more, with the remainder being substantially Fe and unavoidable impurities is quenched from a temperature of 1,030 C. to 1,140 C. and subjected to a subzero treatment and tempering so as to obtain a prior austenite crystal grain size of a surface layer of 30 m to 100 m and a surface hardness of 58 HRc to 62 HRc.

A martensitic stainless steel containing, by mass %, C: 0.20% to 0.40%, N: 0.1% or less, Mo: 3% or less, and Cr: 12.0% to 16.0%, such that 0.3%C+N0.4% and a PI value (=Cr+3.3Mo+16N) is 18 or more, with the remainder being substantially Fe and unavoidable impurities is quenched from a temperature of 1,030 C. to 1,140 C. and subjected to a subzero treatment and tempering so as to obtain a prior austenite crystal grain size of a surface layer of 30 m to 100 m and a surface hardness of 58 HRc to 62 HRc.

A stator magnetic core and manufacturing process thereof and brushless motor comprising the stator magnetic core, wherein the stator magnetic core is made of iron-based amorphous material containing Co and V, and the composition of the iron-based amorphous material by weight percentage is: Co 0.8-1.4%, V 0.6-1.2%, B 2.7-3.3%, Si 6.5-8%, and Fe for the rest. A brushless DC motor, comprising a rotor spindle, a front end cover, a housing, a stator magnetic core and a rear end cover, wherein the stator magnetic core is assembled inside the housing, a stator coil is disposed inside the stator magnetic core, and the stator magnetic core and the stator core don't contact each other and an insulating layer is formed between them. The stator magnetic core in the present invention is made of iron-based amorphous material containing Co and V. Through addition of Co and V elements, the stator magnetic core refines crystalline grain and raises material toughness. It not only overcomes the previous problem of difficult machining and shaping but also raises the efficiency of the brushless DC motor containing this stator magnetic core. It is a breakthrough process.

A method is disclosed for producing a coated body hardened by hot forming. The base body is austenitized in a method step. The coating of the precoated base body is oxidized artificially prior to this method step. A body produced according to the method has an oxidized layer with a thickness of between 0.05 m and 30 m.

The present invention relates to a quenching apparatus capable of quickly reversing a flow of cooling gas flowing in a chamber. The quenching apparatus includes: a chamber provided with a gas inlet and a gas outlet and having an object charged therein; a pair of flow generating means disposed on both sides of the chamber and generating a flow of gas in the chamber; and a flow direction reversing means disposed in the chamber and reversing a flow direction of gas to make the gas flow in any one of a first flow direction in which the gas flows from top to bottom of the object and a second flow direction in which the gas flows from the bottom to the top of the object.

A roll-transport device including: a roll that comes into contact with the base material; a support shaft that rotatably supports the roll; and a bearing that is disposed on an outer peripheral surface of the support shaft and has an end surface on one side in an axial direction, which faces an inside of a furnace, and an end surface on the other side in the axial direction, which is positioned on a side of an inner portion (space surrounded by the roll). A purge gas is caused to circulate from the end surface on the other side toward the end surface on the one side of the bearing, and the purge gas is discharged into the furnace from the end surface on the one side of the bearing.

There are provided: an Ni-based alloy member including a phase precipitation with 36 to 60 volume % and exhibiting a high durable temperature and good cold workability; a method for producing the member; an Ni-based alloy product to be used as a precursor of the member; and a method for producing the product. The Ni-based alloy product has a two-phase structure composed of a phase and a phase being incoherent to the phase, the incoherent phase being present at a ratio of 20 volume % or higher. The Ni-based alloy member produced by cold working the Ni-based alloy product and subsequently by conducting heat treatment comprises a phase and a phase being coherent to the phase, the coherent phase being present at a ratio of 36 to 60 volume %, and has a predetermined shape.