Kawasaki Steel Corporation

Kabushiki Kaisha Riken

Akio Shinohara

Kei Sakata

Yoshitsugu Suzuki

Osamu Furukimi

Kazunori Osawa

Yoichi Tobiyama

Chiaki Kato

Masaki Moronuki

Katsuhiro Tsuji

Takashi Kobayashi

The present disclosure is a combination of a cylinder and a piston ring, the combination including a cylinder of an internal combustion engine and a piston ring sliding on an inner peripheral surface of the cylinder. The piston ring has an outer peripheral surface sliding on the inner peripheral surface of the cylinder, and the outer peripheral surface is formed of a substantially hydrogen-free amorphous carbon coating. The Vickers hardness Hd of the amorphous carbon coating and the Vickers hardness Hb of the inner peripheral surface of the cylinder satisfy Hd+Hb&#x2264;2500 HV. The ratio ID/IG of the peak intensity of the D band to the peak intensity of the G band in a Raman spectrum obtained by measuring the amorphous carbon coating by Raman spectroscopy is 0.60 or more and 1.33 or less.

Combination of cylinder and piston ring

The provided sliding member has both excellent wear resistance and excellent coating adhesion even under harsh sliding conditions. The disclosed sliding member () is used in the presence of a lubricating oil and includes a base member (), a metal intermediate layer () formed on the sliding surface (A) side of the base member, a layered carbon coating () formed on the metal intermediate layer and having a first carbon coating () and a second carbon coating () layered alternately therein, and a hard carbon coating () formed on the layered carbon coating. Under bright-field observation with a transmission electron microscope, an image of the first carbon coating () is brighter than an image of the second carbon coating (). Furthermore, 10 nm&#x3c;T&#x2264;1000 nm and 0.010&#x2264;T/T&#x2264;0.60, where Tand Tare the thicknesses of the first and second carbon coatings ().

Sliding member and piston ring

A combination of a cylinderof an internal combustion engine and a piston ringfor sliding an inner periphery of the cylinder, wherein at least a sliding face of the cylinder is composed of an aluminum alloy including 8 mass % to 22 mass % of Si and at least one or more particles selected from the group consisting of Si, AlOand SiOparticles each having a diameter of 3 &#x3bc;m or more, and at least an outer periphery of the piston ring is coated with a hard carbon coatingcomposed only of hydrogen and carbon.

Method for producing hot-dip galvanized steel sheet having high strength and also being excellent in formability and galvanizing property

A steel sheet having a composition comprising C: 0.05-0.20 mass %, Si: 0.3-1.8 mass %, Mn: 1.0-3.0 mass %, Fe of the balance and inevitable impurities is subjected to a primary step of primary heat treatment and subsequent rapid cooling to Ms point or lower, a secondary step of secondary heat treatment and subsequent rapid cooling, and a tertiary step of galvanizing treatment and rapid cooling, so as to turn the structure of the steel sheet into a composite structure of 20% or more by volume of tempered martensite, 2% or more by volume of retained austenite, ferrite and a low-temperature transformation phase. A galvanized layer is deposited on the surface of the steel sheet. It is preferred to cool the steel sheet to 300&deg; C. at a cooling rate of 5 &deg; C./sec. or more after the galvanizing treatment. After the galvanizing treatment, alloying treatment may be conducted.

High tensile hot-dip zinc-coated steel plate excellent in ductility and method for production thereof

The present invention provides a high strength thin excellent workability and galvanizability, having a composition comprising from 0.01 to 0.20 wt. % C, up to 1.0 wt. % Si, from 1.0 to 3.0 wt. % Mn, up to 0.10 wt. % P, up to 0.05 wt. % S, up to 0.10 wt. % Al, up to 0.010 wt. % N, up to 1.0 wt. % Cr, from 0.001 to 1.00 wt. % Mo, and the balance Fe and incidental impurities, wherein a band structure comprising a secondary phase has a thickness satisfying the relation Tb/T&lE;0.005 (where, Tb: average thickness of the band structure in the thickness direction of steel sheet; T: steel sheet thickness), and a manufacturing method thereof, and a manufacturing method of a high strength hot-dip galvanized steel sheet or a high strength galvannealed steel sheet applying hot-dip galvanizing or further galvannealing, and giving an excellent workability, a high tensile strength, and excellent galvanizability, coating adhesion and corrosion resistance.

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Tokyo, Japan

Akio Shinohara