Hitachi Metals, Ltd.

Nippondenso Co., Ltd.

Toshio Okuno

Katsuaki Fukushima

Masakazu Ito

Keizo Takeuchi

Kingo Kiyonaga

Toshiaki Terada

Yoshihiro Minagi

Tamiya Kishida

Atushi Kumagai

Mitsuru Suzuki

Kenji Tokuda

Katuaki Fukushima

Atsusuke Nakao

A high-strength stainless steel for use as a material of a fuel injection nozzle or a fuel injection needle of an internal combustion engine. The stainless steel is an as annealed martensitic stainless steel which exhibits a hardness not less than HRC 58 after quenching and tempering heat-treatment. The limit swaging ratio of said as annealed martensitic stainless steel is not less than 75%. The hardness of said as annealed martensitic stainless steel is not higher than HB 157. Preferably, the number of carbides having sizes of 0.2 .mu.m or less occupies not more than 50% of the total carbides, and wherein the limit swaging ratio of said as annealed martensitic stainless steel is not less than 75% or the hardness of said as annealed martensitic stainless steel is not higher than HB 157. Preferably, the stainless steel has a chemical composition containing, by weight: 0.4 to 0.6% of C; not more than 0.5% of Si; not more than 0.5% of Mn; 8.0 to 13.0% of Cr; 0.1 to 2.0% of one or both of W and Mo in terms of W/2+Mo; one or both of 0.05 to 1.0% of one or both of Nb and V in terms of Nb/2+V, and 0.2 to 2.0% of Co; and the balance substantially Fe and incidental impurities.

High-strength stainless steel for use as material of fuel injection

The present invention provides a material which is superior in all of peel resistance, corrosion resistance and abrasion resistance against alcoholic fuels. The material comprises an Fe-Cr-C based steel or Fe-Cr-C-Cu based steel. For applications wherein members formed from the material are subjected to impacts, the Cr content is within the range of at least 8.0% and less than 16.0%, the relation between the C content and the Cr content satisfies % Cr+25.times.% C.ltoreq.32 based on weight, and the ratio of the area of a primary carbide to the total sectional area of the material is 1.5% or less. For non-impact applications Cr content is more than 12.0% and less than 16.0%, % C and % Cr satisfy % Cr+25.times.% C&gt;32, and the ratio of the area of a primary carbide to the total sectional area of the material is 8.0% or less. This material is especially superior in peel resistance against alcoholic fuels. The Fe-Cr-C based steel may optionally contain Cu, Si, Mn, W, Mo, V, Co, and Ni.

Materials and members for apparatuses using alcoholic fuels, which are

A high fatigue strength metal band saw backing material of the present invention comprises 0.27 to 0.40% of C, not more than 0.35% of Si, 0.3 to 1.2% of Mn, 0.45 to 0.75% of Ni, more than 3.0% to 4.5% of Cr, 1.5 to 2.3% of one or two of Mo and W in terms of 'Mo+W/2', 0.03 to 0.2% of one or two of V and Nb in terms of 'V+Nb/2', in terms of percent by weight, the balance Fe and inevitable impurities. The metal band saw can maintain its high fatigue strength even if it is subjected to heat treatment under the same conditions as those for high speed steel used as an edge material and thus exhibits excellent properties as a metal band saw backing material.

High fatigue strength metal band saw backing material

Isotropic tool steel consisting essentially of necessary elements as tool steel, less than 0.005 weight % of S and less than 30 ppm of O, the balance being substantially Fe. The necessary elements are, by weight, 0.10-0.70% of C, 2.00% or less of Si, 2.00% or less of Mn, 7.00% or less of Cr, 0.20-12.00% of W and/or Mo alone or in combination (1/2W+Mo), 3.00% or less of V. They may further include at least one of 4.00% or less of Ni, 6.50% or less of Co and 0.20% or less of N. The isotropic tool steel has cleanliness with respect to non-metallic inclusions defined by JIS G 0555 of dA60.times.400.ltoreq.0.010% and d(B+C)60.times.400.ltoreq.0.020%, and a ratio of transverse direction toughness to longitudinal direction toughness of more than 0.70. Since it is highly resistant to the generation and propagation of cracks and fracture, dies for hot working made therefrom can enjoy a long life.

Isotropic tool steel

A steel which consists essentially of 0.25-0.65% of C, up to 2.50% of Si, up to 2.00% of Mn, 10.00-20.00% of Cr, 4.00-13.00% of Co, 1.00-3.00% of Al, up to 0.25% of N and the balance essentially Fe and ordinary impurities and satisfies the relation:

Fully martensitic steel for a metal mold for molding glass and the metal

The present invention relates to a tool steel for warm and hot working which consists essentially of, by weight, 0.50 - 1.00% of C, up to 1.50% of Si, up to 1.50% of Mn, 0.70 - 1.50% of Ni, 3.00 - 4.50% of Cr, 1.3 - 5.0% of W, 4.2 - 9.0% of Mo, 1.30 - 3.00% of V, 0.9 - 6.0% of Co, and the balance essentially Fe and impurities and 0.15 + 0.2 V .ltoreq. C .ltoreq. 0.42 + 0.2 V. This tool steel is especially high in warm and hot strengths and abrasion resistance and has excellent toughness and hardenability.

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Yasugi, Japan

Toshio Okuno