Nippon Steel Corporation

Yasuo Otoguro

Mikio Yamanaka

Katukuni Hashimoto

Toshio Fujita

Takashi Zaizen

Hisashi Takahashi

Satoshi Kado

Takao Yokokawa

Mizuo Sakakibara

Teruo Ikeno

Yasuhiko Miyoshi

Sigeyuki Akase

Shogo Kanazawa

Masao Onoyama

Nobukazu Suzuki

Tadao Azami

Noboru Miida

Tadahisa Akazawa

Shozo Yamane

Kazuya Kuroiwa

Chuichi Kato

A high-strength, heat-resisting ferritic steel pipe or tube for boiler use containing 0.03 to 0.15% C, 0.1 to 1.5% Mn, 8 to 13% Cr, 1.8 to 3.0% W, 0.05 to 0.30% V, 0.02 to 0.12% Nb, 0.02 to 0.05% N, 0.02 to 0.4% Mo, and up to 0.25% Si. This pipe or tube has an improved high-temperature creep rupture strength and an excellent weldability and toughness.

High-strength heat-resisting ferritic steel pipe and tube

A high-Al heat resistant steel comprising a base steel containing not more than 0.7% C, not more than 3.0% Si, not more than 2.0% Mn, 10 to 40% Ni, 9 to 30% Cr, 2 to 8% Al, with balance being Fe and unavoidable impurities, and an Al coating formed on the base steel. The Al coating diffuses into the base steel to form an intermediate Al alloyed layer during the Al coating or by heating after the coating, which alloyed layer prevents the Al coating from spalling, thus providing excellent resistance to oxidation, corrosion, carburization, nitrization and sulphurdization at elevated temperatures.

High Al heat-resistant alloy steels having Al coating thereon

In a continuous annealing furnace, a steel strip is conveyed by conventional hearth rolls made of heat-resistant cast steel, such as HK 40. However, since the formation of buildup is frequent, conventional hearth rolls are inappropriate for long-term operation of a continuous annealing furnace. In the hearth roll of the present invention, which consists of a solid or hollow roll body and a surface layer, the surface layer containing more than 15% by weight of Nb and the balance being inorganic material, the formation of buildup is not frequest, thereby making long-term operation of a continuous annealing furnace possible.

Highly buildup-resistant hearth roll for conveying a steel strip through

A boiler tube having improved high temperature strength, improved high temperature corrosion resistance, and resistivity to embrittlement during the service thereof, comprising an outer surface layer and an inner part, the outer surface layer consisting essentially, by weight, of 0.03-0.20% carbon, 1.5-4.0% silicon, 0.1-3.0% manganese, 13-25% chromium, 13-40% nickel, 0.5-3.0% at least one kind selected from the group consisting of molybdenum and tungsten, 0.05-0.5% at least one kind selected from the group consisting of titanium, niobium and vanadium, and the balance iron and inevitable impurities, the inner part consisting essentially, by weight, of 0.03-0.20% carbon, 0.3-1.0% silicon, 0.1-3.0% manganese, 13-25% chromium, 13-40% nickel, 0.5-3.0% at least one kind selected from the group consisting of molybdenum and tungsten, 0.05-0.5% at least one kind selected from the group consisting of titanium, niobium and vanadium, and the balance iron and inevitable impurities. Boron of 0.001-0.01% may be further added to the alloy to improve creep strength while keeping improved high temperature corrosion resistance.

Boiler tube having improved high temperature mechanical strength,

A ferritic heat-resisting steel with an excellent toughness comprises

Ferritic heat-resisting steel with an excellent toughness

A stainless steel pipe having a surface layer with excellent resistance against vanadium pentoxide attack experienced upon boiler heating tubes for power generation, corrosion by sulfates, corrosion by chlorides experienced upon boiler heating tubes for various burning furnace and high-temperature gas corrosion experienced upon tubes for heating furnaces in the chemical industry, and also relates to methods for forming the surface layer.

Stainless steel products, such as sheets and pipes, having a surface

A free cutting graphitic steel comprising:

Free-cutting graphitic steel

Growing community of inventors

Sagamihara, Japan

Yasuo Otoguro