Abstract: A method for a surface treatment of a metal material, which comprises subjecting a metal material such as an Fe alloy, a Ni alloy and an Al alloy to a heat treatment in the presence of an amino-based resin such as a melamine-formaldehyde resin. The amino-based resin can be caused to be present with the metal material by a method wherein the resin is applied on the surface of the metal material, directly or via a solvent such as water, or wherein the amino-based resin is placed in a container, and the container and the metal material are placed in a heat treatment furnace. The above heat treatment allows a passivated film to disappear from the metal material. Further, a subsequent elevation of temperature and the supply a nitriding gas allows the performance of a nitriding treatment being several times more effective than a conventional treatment, and a subsequent supply of a carburizing agent allows the performance of a carburizing treatment.

Abstract: When a metal material such as an Fe alloy or Ni alloy is heated in the presence of an amino resin such as a melamine-formalin resin, a passivation film on the surface of the metal material is reduced and removed. During the reduction and removal of the passivation film, hydrogen sputtering may be also performed when the temperature becomes higher than 400° C., preferably not less than 450° C. By performing a glow discharge, the metal material having an exposed active metal surface is nitrided with N liberated from the amino resin. For example, the amino resin is applied onto the surface of the metal material directly or by using a solvent such as water.

Abstract: Long work of Fe based alloy while being rotated at a given rotation speed under the action of rotating chucks is heated by high-frequency heating coil to thereby accomplish the heating step. In the first cooling step after termination of the heating, the long work while having its rotation speed increased is brought into contact with first to fourth correction rollers, and in that state is cooled so as to fall within a temperature range of Pf temperature or below to over Ms temperature. The time spent in the cooling preferably ranges from 5 to 10 sec. In the subsequent second cooling step, the rotation speed of the long work is reduced, preferably so as to be equal to that at the heating, and cooling of the long work is continued.

Abstract: A method for producing s connecting rod, wherein the vicinity of the bottom portion of a notch, which is planed to be broken in a pre-formed article for the connecting rod, is irradiated with a laser light, a plasma or the like, and when the irradiated bottom portion is allowed to cool in air, an austenite structure is transformed into a martensite structure, which results in the formation of a martensite portion in the vicinity of the bottom portion of a notch.

Abstract: A method for a surface treatment of a metal material, which comprises subjecting a metal material such as an Fe alloy, a Ni alloy and an Al alloy to a heat treatment in the presence of an amino-based resin such as a melamine-formaldehyde resin. The amino-based resin can be caused to be present with the metal material by a method wherein the resin is applied on the surface of the metal material, directly or via a solvent such as water, or wherein the amino-based resin is placed in a container, and the container and the metal material are placed in a heat treatment furnace. The above heat treatment allows a passivated film to disappear from the metal material. Further, a subsequent elevation of temperature and the supply a nitriding gas allows the performance of a nitriding treatment being several times more effective than a conventional treatment, and a subsequent supply of a carburizing agent allows the performance of a carburizing treatment.

Abstract: A sludge trapping container has a side wall and a bottom each having a plurality of holes defined therein by electron beam machining. Each of the holes has a tapered shape such that the diameter D1 of an end thereof opening at an outer wall surface of the sludge trapping container is smaller than the diameter D2 of an end thereof opening at an inner wall surface of the sludge trapping container. The sludge trapping container is economical as it is suitable for repeated use, and can trap a sludge highly efficiently and can be cleaned highly efficiently because of the gradient of inner surfaces of the holes.

Abstract: A ferrite core partly covered with ceramics members is loaded into an oil hole defined in a pin, and high-frequency induction hardening is effected on the pin while the ferrite core is being held in position by copper wires. At the same time, a magnetic field is generated from the ferrite core to produce a high-frequency induction hardened layer having progressively spreading skirt regions extending from a position in the vicinity of a center in an axial direction of the oil hole toward openings in ends of the oil hole.

Abstract: A ferrite core partly covered with ceramics members is loaded into an oil hole defined in a pin, and high-frequency induction hardening is effected on the pin while the ferrite core is being held in position by copper wires. At the same time, a magnetic field is generated from the ferrite core to produce a high-frequency induction hardened layer having progressively spreading skirt regions extending from a position in the vicinity of a center in an axial direction of the oil hole toward openings in ends of the oil hole.