Abstract: A metal gasket for an internal combustion engine includes a first metal plate with a folded portion; a ring member with a sandwiched portion having a sealing bead and an extension portion, with the sandwiched portion being sandwiched in the folded portion to provide a primary sealing portion; a second metal plate laminated to the folded portion of the first metal plate so as to sandwich the extension portion to provide a secondary sealing portion; and a third metal plate sandwiched between the first metal plate and the second metal plate in a portion of the gasket separate from the sandwiched extension portion. In the event that the cylinder head lift becomes greater than the following capability of the sealing bead in the primary sealing portion, the secondary sealing portion provides excellent following capability relative to the lift.

Abstract: An electric current bonding apparatus, comprising: a plurality of metallic members 101, 102 through which electric current is capable of flowing; a pressurizing unit 2a1, 2a2, 2b for applying pressing forces to the plurality of metallic members 101, 102 so as to press the metallic members against each other; a plurality of paired electrodes 12a, 12b disposed on the plurality of metallic members 101, 102 to heat the metallic members by use of resistance heat generated by a flow of electric current; a power supply 6a, 6b for supplying electric current to the plurality of paired electrodes; and an energizing controller 5 for supplying electric current from the power supply to the plurality of electrodes by making a switchover to an electrode pair across to supply the electric current.

Abstract: A metal laminate gasket is formed of at least three metal plates, i.e. first to third metal plates assembled together. A connecting portion is formed for partially connecting the first and second metal plates. The third metal plate has an opening located at a position facing the connecting portion for receiving the connecting portion therein. Thus, local pressure formed at the connection portion when the gasket is tightened is eliminated.

Abstract: A gasket is formed of a metal plate, and includes a plurality of coating layers laminated on the metal plate. The coating layers may be a first coating layer laminated on the metal plate and at least one second coating layer laminated on the first laminating layer. An internal-layer confirmation portion is provided in a part of the second coating layer where the second coating layer is not formed so that presence or absence of the first coating layer is seen through the internal-layer confirmation portion.

Abstract: A resistance bonding method comprises contacting a plurality of bonding members, which are electro-conductive, supplying current to the bonding members under a stress applied to a contact interface therebetween by means of plural electrodes in contact with the bonding members thereby to bond the members. The current supply is conducted by switching energizing paths. Part of the members is thermally expanded by current supply before one of the bonding members is contacted with other member, and the members in contact with each other are bonded by the second current supply.

Abstract: A metal laminate gasket with a hole to be sealed includes a base metal plate having a first hole corresponding to the hole to be sealed, and a first steel plate laminated on one side of the base metal plate and having a second hole with a diameter greater than that of the first hole. The second hole has an inner surface and is aligned with the first hole when the base metal plate and the first steel plate are laminated. A coating layer is deposited on the first steel plate and has a portion deposited on the inner surface of the second hole.

Abstract: A metal gasket for an internal combustion engine includes a first metal plate with a folded portion; a ring member with a sandwiched portion having a sealing bead and an extension portion, with the sandwiched portion being sandwiched in the folded portion to provide a primary sealing portion; a second metal plate laminated to the folded portion of the first metal plate so as to sandwich the extension portion to provide a secondary sealing portion; and a third metal plate sandwiched between the first metal plate and the second metal plate in a portion of the gasket separate from the sandwiched extension portion. In the event that the cylinder head lift becomes greater than the following capability of the sealing bead in the primary sealing portion, the secondary sealing portion provides excellent following capability relative to the lift.

Abstract: A novel treatment method, for improving fatigue life, is provided that aims to resolve problems associated with conventional treatment methods for improving fatigue life of metal by reduction of stress concentration and conventional treatment methods for improving fatigue life of metal by introduction of compressive stress, that is, problems of poor efficiency in work execution, required level of skill of workers, and the impossibility of quality control due to lack of means for measuring the effect after treatment, characterized in that, for locations in metal for which fatigue is a problem, after pre-treatment is performed, ultrasonic impact treatment is performed, and thereafter, a quality assurance test is performed so as to improve the fatigue life of the metal.

Abstract: A metal laminate gasket with a hole to be sealed includes a base metal plate having a first hole corresponding to the hole to be sealed, and a first steel plate laminated on one side of the base metal plate and having a second hole with a diameter greater than that of the first hole. The second hole has an inner surface and is aligned with the first hole when the base metal plate and the first steel plate are laminated. A coating layer is deposited on the first steel plate and has a portion deposited on the inner surface of the second hole.

Abstract: A metal gasket for an internal combustion engine is formed of a metal plate including a base portion extending substantially throughout an entire area to be sealed, at least one hole formed in the base portion, a curved portion extending from the base portion, and a flange extending from the curved portion and disposed on a part of an upper surface of the base portion. A coating member is deposited on the flange facing the base portion and/or the base portion facing the flange. The coating member is formed of a non-thermoplastic coating material to operate as a surface pressure regulating member between the flange and the base portion to thereby regulate a surface pressure at the flange.

Abstract: A metal gasket for an internal combustion engine is formed of a metal plate including a base portion extending substantially throughout an entire area to be sealed, at least one hole formed in the base portion, a curved portion extending from the base portion, and a flange extending from the curved portion and disposed on a part of an upper surface of the base portion. A coating member is deposited on the flange facing the base portion and/or the base portion facing the flange. The coating member is formed of a non-thermoplastic coating material to operate as a surface pressure regulating member between the flange and the base portion to thereby regulate a surface pressure at the flange.

Abstract: In order to conduct welding so that the welded steel shows a decreased residual stress after welding without a post treatment such as a PWHT, the steel for welded structures and the welding wire of the present invention starts a transformation from austenite into martensite at a temperature (Ms temperature) from at least 200° C. to up to 350° C., and has a yield strength from at least 60 kg/mm2 to up to 120 kg/mm2 at the transformation starting temperature. The multipass welding process of the present invention comprises forming a weld metal having a Ms temperature of 150° C. to 300° C., and TIG remelt-run welding the surface of the final layer.

Abstract: In the present invention, a steel product having a specified composition comprising by weight C: 0.02 to 0.25%, Si: 0.01 to 2.0%, Mn: 0.30 to 1.5%, Al: 0.003 to 0.10%, Nb: 0.005 to 0.10%, and Mo: 0.05 to 1.00% with the balance consisting of Fe and unavoidable impurities is used to prepare a steel plate having a thickness of 3 to 100 mm (the upper limits of the Nb and Mo contents each being 0.025% particularly for a plate thickness of 3 to 25 mm), and the ratio of the yield stress of the steel plate at a temperature T, .sigma..sub.yT, to the yield stress of the steel plate at room temperature, .sigma..sub.y, over the temperature range of room temperature to 600.degree. C. is brought to a value falling within the following range:1.00-1.083.times.10.sup.-3 T<(.sigma..sub.yT /.sigma..sub.y)<1.16-5.101.times.10.sup.-4 T.Further, the constituents of a welding material are specified to bring the .gamma..sub.3 transformation temperature to below 620.degree. C.

Abstract: The present invention relates to a method of reducing an amount of welding deformation in the case where steel plates to be welded are butted and subjected to tack-welding and then the tack-welded portion is subjected to one side welding for joining the plates.In the present invention, not less than 3 welding electrodes are used and a welding condition is determined so that the parameter P shown by the expression of ##EQU1## can be a predetermined value. In this case, Qi is the heat input of each electrode determined by a current, voltage and speed, and Li is a distance from the first electrode to each electrode, and H is the maximum value of the height of a tack-welded bead, wherein the height H is made to be a value not more than half of the wall thickness of the steel plates to be welded.