Abstract: A high-performance stainless steel sheet which has a high strength which is optimal for a gasket for use in high-performance engines of automobiles and motorcycles and which also has excellent workability and fatigue properties and a method for its manufacture are provided. At least in a region from the surface of the sheet up to 3 ?m in the thickness direction, nitrogen compounds of at least 10 nm and at most 200 nm are present in an amount of at least 200 per 100 ?m2. The number of nitrogen compounds of at least 10 nm and at most 200 nm in a region from the sheet surface up to 3 ?m in the thickness direction of the sheet is at least 2 times the number of nitrogen compounds of this size in the central portion of the sheet thickness.

Abstract: Method of manufacturing a metal gasket including a base plate having at least fluid passage holes and circular beads surrounding the fluid passage holes, the base plate being formed by providing a rubber coating layer on a surface of a metal plate with a base coat and an adhesive interposed therebetween. A metal plate having low-temperature age-hardening characteristics is used as the metal plate of the base plate. After the base coat is applied to the metal plate and dried at a temperature lower than a low aging temperature of the metal plate, press-working of the circular beads is performed on the metal plate. Thereafter, the metal plate is age-hardened while burning the base coat at the low aging temperature of the metal plate. A metal gasket having excellent durability and circular beads which are hardly broken even when crushed, is obtained.

Abstract: A high-performance stainless steel sheet which has a high strength which is optimal for a gasket for use in high-performance engines of automobiles and motorcycles and which also has excellent workability and fatigue properties and a method for its manufacture are provided. At least in a region from the surface of the sheet up to 3 ?m in the thickness direction, nitrogen compounds of at least 10 nm and at most 200 nm are present in an amount of at least 200 per 100 ?m2. The number of nitrogen compounds of at least 10 nm and at most 200 nm in a region from the sheet surface up to 3 ?m in the thickness direction of the sheet is at least 2 times the number of nitrogen compounds of this size in the central portion of the sheet thickness.

Abstract: A metal gasket for a cylinder head has two base plates each constructed from a metal plate and layered over each other, an auxiliary plate constructed from a metal plate and interposed between the base plates, and hard metal-plated layers. The base plates each have cylinder holes, annular beads, coolant holes, and an outer peripheral bead. The cylinder holes correspond with the bore of each cylinder. The annular beads have an angled cross-sectional shape. The coolant holes correspond with a coolant jacket of the cylinder block and with a coolant hole of the cylinder head. The outer peripheral bead has a cross-sectional shape sloping on one side and surrounds the beads and the coolant holes. Each of the layers is extended from a position more radially inward than an annular bead of a base plate to a position radially outward.

Abstract: A metal gasket material plate has improved adhesion of a rubber layer to a metal plate by use of an adhesive layer, so as to prevent the rubber layer from happening delamination of the metal plate and to provide a chromium-free material plate in consideration of adverse effects on the environment and a human body. In a laminated metal gasket material plate provided with a rubber layer on a metal plate by use of an adhesive layer, the metal gasket material plate includes silane-based chemical conversion coating being formed between a surface of the metal plate and the adhesive layer by applying a silane coupling agent containing any of an epoxy group, a mercapto group, and an amino group as a functional group. Here, the adhesive layer is made of a phenol resin-based adhesive, and the rubber layer is made of an NBR-based rubber mixture.

Abstract: This invention relates to a stainless steel gasket having markedly improved strength and fatigue properties due to precipitation strengthening. Its composition comprises C: at most 0.03%, Si: at most 1.0%, Mn: at most 2%, Cr: 16.0%-18.0%, Ni: 6.0%-8.0%, N: at most 0.25%, if necessary Nb: at most 0.30%, and a remainder of Fe and unavoidable impurities. After cold rolling, final annealing is carried out, and after a structure is formed of recrystallized grains with an average grain diameter of at most 5 ?m having an area ratio of 50-100% and an unrecrystallized portion having an area ratio of 0-50%, a metal gasket is formed by steps including temper rolling with a reduction of at least 30% to make the area ratio of a strain induced martensite phase at least 40%, and forming and heat treatment at 200-350° C.

Abstract: This invention relates to a stainless steel gasket having markedly improved strength and fatigue properties due to precipitation strengthening. Its composition comprises C: at most 0.03%, Si: at most 1.0%, Mn: at most 2%, Cr: 16.0%-18.0%, Ni: 6.0%-8.0%, N: at most 0.25%, if necessary Nb: at most 0.30%, and a remainder of Fe and unavoidable impurities. After cold rolling, final annealing is carried out, and after a structure is formed of recrystallized grains with an average grain diameter of at most 5 &mgr;m having an area ratio of 50-100% and an unrecrystallized portion having an area ratio of 0-50%, a metal gasket is formed by steps including temper rolling with a reduction of at least 30% to make the area ratio of a strain induced martensite phase at least 40%, and forming and heat treatment at 200-350° C.

Abstract: An austenitic stainless steel for use in engine gaskets having a high fatigue strength and resistance to settlement and method of manufacture thereof. The austenitic stainless steel is prepared by cold rolling at least 40%, annealing at a temperature of 700° C. to 900° C. followed by temper rolling with a reduction of at least 40%. The metal structure obtained by annealing is a recovered unrecrystallized structure or a mixed structure of a recovered unrecrystallized structure and a recrystallized structure. The austenitic stainless steel includes at most 0.03% C, at most 1.0% Si, at most 2.0% Mn, 16.0% to 18.0% Cr, 6.0% to 8.0% Ni and up to 0.20% N.