Hitachi, Ltd.

The Tokyo Electric Power Company, Incorporated

Central Research Institute of Electric Power Industry

Akira Mebata

Yoshitaka Kojima

Hideyuki Arikawa

Hajime Toriya

Tetsuo Sasada

Kunihiro Ichikawa

Norio Watanabe

Mitsuo Haginoya

Yukiyoshi Hara

Ryoichiro Ohoshima

Akihiko Chiba

Hiroyuki Doi

Masahiko Arai

Noriyuki Ohnaka

Kenjiro Narita

Tohru Hisamatsu

Hiroshi Haruyama

Takayuki Yoshioka

Mitsutoshi Okada

Haijime Toriya

Kiyoshi Otake

A metal sealing material used in a sealing device which can reduce a gap between a stator and a rotor of a turbine. The metal sealing material used in a sealing device for a stator and a rotor of a turbine includes a surface layer and a lower layer composed of a porous metal layer, wherein the porosity of the surface layer is smaller than the porosity of the lower layer; the porosity of the surface layer is 60 to 65% and the porosity of the lower layer is 67 to 75% or less; and the porous metal layer has a thickness of 0.3 to 3.0 mm and may include, as a main component, an MCrAlY alloy where M is either one of Ni and Co or both thereof, and h-BN as a solid lubricant.

High-reliability turbine metal sealing material

A steam turbine rotor shaft and method of manufacturing the same are provided wherein the sliding characteristics of a journal are improved, and the journal is free from welding cracks and does not need a post heat treatment. The low alloy steel coating layer having better sliding characteristics than 9 to 13% Cr heat resisting steel and an area rate of defects including pores and oxides in a range of 3 to 15% is formed by a high velocity flame spray coating method on a sliding surface of the journal.

Rotor for steam turbine and method of manufacturing the same

A high-temperature resistant component for, e.g., a gas turbine hot part, includes an alloy substrate containing Ni, Co, or Fe as the principal component, and a thermal barrier coating formed over the surface of the substrate via a bond coat. The thermal barrier coating includes a porous thermal-barrier layer made of ceramic and an environmental barrier layer with corrosion resistance. An impregnated layer is provided between the environmental barrier layer and the thermal barrier layer. In the impregnated layer, the thermal barrier layer is impregnated with a part of the environmental barrier layer. The thermal barrier layer is made of a porous zirconia layer, and the environmental barrier layer includes silica as the principal component. The porous zirconia layer has pores impregnated with the part of the environmental barrier layer. As a result, the high-temperature resistant component has excellent corrosion resistance and excellent heat resistance.

High-temperature resistant component and gas turbine hot part

There is provided a high temperature component with a thermal barrier coating, which can be used as a high temperature component for a gas turbine, an aircraft gas turbine engine, or the like. A top coat is formed of a ceramic on a bond coat, the bond coat being formed on a heat resistant alloy substrate composed mainly of at least one element of nickel and cobalt, wherein the bond coat contains at least one of nickel and cobalt, chromium and aluminum, and further contains at least one selected from a group consisting of tantalum, cesium, tungsten, silicon, platinum, manganese and boron in a range of 0 to 20 wt %. The high temperature component according to the present invention has very high durability of a thermal-insulating ceramic layer, and is less susceptible to spalling damage.

High temperature component with thermal barrier coating and gas turbine using the same

A thermal barrier coating comprises a bond coatingmade of high temperature corrosion resistance superior to a substrateand a thermal barrier coatingmade of ZrO2 series ceramics formed on the bond coating. The thermal barrier coating has cracks extending in the direction of the thickness of the barrier coat. Substantially all of the tips of the cracks have a distance between the tips and the boundary at the substrate side.

Heat resistant article having thermal barrier coating

A ceramic coated heat-resistant element comprises a heat resisting alloy base mainly composed of Ni and/or Co and a heat-resistant coating layer provided on the surface of the base and is characterized in that said heat-resistant coating layer comprises a metal layer of an alloy superior to the base in high-temperature corrosion and oxidation resistance and provided on the base, an Al.sub.2 O.sub.3 ceramic thin film layer provided on the metal layer, a ZrO.sub.2 ceramic coating layer having dense texture provided on the Al.sub.2 O.sub.3 ceramic thin film layer and a ZrO.sub.2 ceramic coating layer having columnar texture provided on the ZrO.sub.2 ceramic coating layer having dense texture cracks are present only in the ZrO.sub.2 ceramic coating layer having columnar texture in the direction of thickness along the boundary of the columns. A mixed layer composed of a metal superior to the base in high-temperature corrosion and oxidation resistance and a ZrO.sub.2 ceramic may be provided between the base and the metal layer.

Thermal stress relaxation type ceramic coated heat-resistant element and

The present invention provides ceramic coated heat-resistant elements which suffer no damages even under high heat load conditions and can afford a thermal barrier effect stably for a long period of time and can be used, for example, as buckets and stationary blades of turbines. A method for making the elements is also provided. The ceramic coated heat-resistant element comprises a heat resisting alloy base mainly composed of Ni and/or Co and a heat-resistant coating layer provided on the surface of the base and is characterized in that said heat-resistant coating layer comprises a metal layer of an alloy superior to the base in high-temperature corrosion and oxidation resistance and provided on the base, an Al.sub.2 O.sub.3 ceramic thin film layer provided on the metal layer, a ZrO.sub.2 ceramic coating layer having dense texture provided on the Al.sub.2 O.sub.3 ceramic thin film layer and a ZrO.sub.2 ceramic coating layer having columnar texture provided on the ZrO.sub.2 ceramic coating layer having dense texture and cracks are present only in said ZrO.sub.2 ceramic coating layer having columnar texture in the direction of thickness along the boundary of the columns. A mixed layer composed of a metal superior to the base in high-temperature corrosion and oxidation resistance and a ZrO.sub.2 ceramic may be provided between the base and the metal layer.

Thermal stress relaxation type ceramic coated heat-resistant element

A coated layer of this invention is composed of a lower alloy-coated layer 2 formed of an MCrAlY alloy whose principal element is Co or Co and Ni, an upper alloy-coated layer 1 formed of an MCrAlY alloy whose principal element is Ni and a portion 4 in which an Al content of the surface portion of the upper coated layer 1 is largest and is reduced gradually towards a more internal part. Manufacturing thereof involves the steps of forming the lower and upper coated layers and effecting an Al diffusion treatment into the upper coated layer. The upper coated layer having the portion which exhibits the large Al content contributes to a high-temperature anticorrosive property. A gas turbine blade is provided with the alloy-coated layer, wherein the lower coated layer incorporates a composite function to prevent a high-temperature corrosion of a base material when cracks are caused in the upper coated layer due to thermal stress. The gas turbine blade exhibits effects of improving the reliability and increasing a life-time.

Alloy-coated gas turbine blade and manufacturing method thereof

A gas turbine bucket and a gas turbine nozzle applied with a ceramic coating comprises a base material of the bucket and the nozzle made of a heat resisting alloy; a plurality of coating layers for the front portion consisting of, a mixture layer which comprises a ceramic material and metal and which is formed on the base material, an alloy layer which comprises an alloy material exhibiting excellent resistance to high temperature oxidation and corrosion and which is formed on the mixture layer, and a ceramic layer which comprises ceramic material and formed on the alloy layer. Such ceramic coating has a satisfactory thermal barrier effect on the base material of the gas turbine bucket and nozzle.

Ceramics-coated heat resisting alloy member

A ceramic-coated heat resisting alloy member comprises a base metal mainly composed of at least one of nickel, cobalt and iron; a mixture layer which is deposited on the external surface of the base metal and which comprises a ceramics and a metal; an alloy layer which is formed between the mixture layer and a ceramic coating layer formed as an outermost layer and which comprises an alloy material exhibiting excellent resistance to high temperature oxidation and excellent resistance to high temperature corrosion. It is therefore possible to prevent any high temperature oxidation and high temperature corrosion of the mixture layer and to enable the mixture layer to have a satisfactory function of reducing the thermal stress produced between the ceramic coating layer and the base metal. The ceramic coating thus has a satisfactory thermal barrier effect on the base metal. In addition, it is therefore possible to provide the ceramic-coated heat resisting alloy member as a useful structural member for improving the power efficiency of gas turbine plants used for power generation.

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Kitaibaraki, Japan

Akira Mebata