Hitachi Metals, Ltd.

Norimasa Uchida

Hideki Nakamura

Junichi Nishida

Kingo Kiyonaga

Keiji Yamasaki

Yutaka Kubo

The present invention provides a vane material having an excellent scuffing resistance in a compressor employing an alternative Freon gas as a cooling medium and a process for the preparation thereof. In accordance with the present invention, a vane material is provided having a structure comprising a base material consisting essentially of 1.0 to 4.5% by weight of carbon, not more than 1.5% by weight of silicon, not more than 1.0% by weight of manganese, 3 to 6% by weight of chromium, not more than 30% of tungsten and/or not more than 20% by weight of molybdenum provided that (W+2Mo) is not more than 45% by weight, 2 to 10% by weight of vanadium and/or niobium, not more than 20% by weight of cobalt, and a balance of iron and inavoidable impurities with additive particles of a carbide and additive particles of a nitride and/or a carbonitride, sintered thereto in an amount of more than 0% to not more than 25% by weight and 2 to 25% by weight based on the total weight of the vane material, respectively. The vane material according to the present invention can be obtained by sintering the mixture of the base powder with the particulate carbide and nitride or carbonitride powders.

Vane material and process for preparing same

Disclosed is a high-speed steel member and manufacturing method thereof. The member has Nb content of 0(incl.) to 2.0 (excl.) % in the hard state after hardening and tempering and in its micro-structure, contains either or both of M.sub.6 C and M.sub.2 C type carbides representing a rate of 0 to 2% to the total area, and the remainder substantially consisting of MC type carbide. The difference of crystallization temperatures is 30.degree. C. or more between MC type carbide and M.sub.6 C or M.sub.2 C type eutectic carbide. The high-speed steel member exhibits a high toughness and a small anisotropy of the mechanical property namely, a hardness of HRC 60 or more and a Charpy impact value ratio between the longitudinal direction and the direction perpendicular thereto in a forged material is 0.7 or more and are quite useful for plastic working.

High toughness high-speed steel member and manufacturing method

Vane material, vane and method of producing a vane to be used in a compressor using a substitute freon, improving the wear resistance thereof. The vane material has a composition consisting of by weight: 1.0-2.5% of C; not more than 1.5% of Si; not more than 1.0% of Mn; 3-6% of Cr; one or two of not more than 20% W and not more than 12% Mo where 'W+2Mo' being 15-28%; 3.5-10% of one or two of V and Nb; and the balance of Fe and incidental impurities. Carbides are uniformly dispersed in the matrix thereof where their average diameter does not exceed 1.5 .mu.m and the maximum diameter thereof does not exceed 6 .mu.m. A method of producing a vane is also disclosed, in which an atomized powder having the composition as described is compacted and it is then subjected to hot working, or to hot working and cold working.

Vane material, vane, and method of producing vane

A high speed tool steel produced by sintering powder, consisting essentially, by weight, of more than 1.5% but not more than 2.2% C, not more than 1.0% Si, not more than 0.6% Mn, 3.0 to 6.0% Cr, an amount of W and Mo in which the content of W+2Mo is in the range of 20 to 30% and in which the ratio of W/2Mo is not less than 1, not more than 5.0% V, 2.0 to 7.0% Nb, the ratio of Nb/V being not less than 0.5, and the balance Fe and incidental impurities, the value of C-Ceq, which Ceq is defined by 0.24+0.033.times.W+0.063.times.Mo+0.2.times.V+0.1.times.Nb, being in a range of -0.20 to 0.05, the density of carbides in the sintered steel having grain size of 2 to 5 .mu.m being in a range of 10,000 to 30,000 pieces/mm.sup.2.

High speed tool steel produced by sintering powder and method of

A powder metallurgy wire for a dot printer is disclosed which consists, by weight, of 1.5 to 2.8% C, 7.5 to 12.0% Cr, at least one kind selected from the group consisting of not more than 18.0% W and not more than 11.0% Mo which W and Mo meet the relationship of 12.ltoreq.W+2Mo.ltoreq.22, 3 to 10% V, 1.0 to 10% Co, not more than 1.0% Si, not more than 1.0% Mn, the balance Fe and incidental impurities, the value of the difference of (C-Ceq) being in the range of -0.5 to -0.15 where Ceq=0.06.times.%Cr+0.033.times.%W+0.063.times.%Mo+0.2.times.%V. According to the composition, corrosion resistance and wear resistance are considerably improved, with light weight and high toughness.

Wire for dot printer

A super hard high-speed tool steel having a composition satisfying the condition of 0.ltoreq.C-Ceq.ltoreq.0.6 (where Ceq=0.06Cr+0.033 W+0.063 Mo+0.2 V within the range of 1.7.ltoreq.C.ltoreq.4.1%, the composition containing 3 to 10% of Cr, 1 to 20% of W, 1 to 15% of Mo (where 18.ltoreq.W+2Mo.ltoreq.40), 1 to 15% of V, not greater than 15% of Co, not greater than 2% of Si, not greater than 1% of Mn, and the balance substantially Fe and inevitable impurities, the steel further containing in uniformly dispersed state 2 to 12% in total of one, two or more selected from a group consisting of nitrides, carbides and carbonitrides of Ti, V, Zr, Nb, Hf and Ta in the composition. This tool steel exhibits a distinguished hardness of HRC 71 or higher, as well as toughness.

Super hard high-speed tool steel

A method for treating surfaces is provided, in which a material to be treated, such as iron, iron alloys or the like is immersed in a molten bath prepared by adding 5 to 50 weight % of a metal cementing agent consisting of one or more selected from the group consisting of a Group Va element, a substance containing the Group Va element, a Group VIa element and a substance containing the Group VIa element to a salt bath agent consisting of a neutral salt containing 5 to 30 mol % of a borate admixed therewith, to form the carbide of the Group Va element or Group VIa element or the composite carbide of these elements on the surfaces of the material. To the molten bath there may be optionally added 1 to 10 weight % of an adjuvant consisting of one or more selected from the group consisting of the oxysalts of the Groups IVa, Va and VIa elements and/or 1 to 10 weight % of a metal or an alloy thereof selected from the group consisting of a Group IVa metal and an alloy thereof.

Method for treating surfaces

A high speed tool steel having high toughness as well as excellent wear resistance and heat resistance characteristics, this steel contains, by weight, C 0.7 - 1.4%, Si 0.5% max., Mn 0.5% max., Cr 3 - 6%, W 1 - 3.2%, Mo 5.5 - 7.5%, V 1 - 3.5%, Co 15% max., N 0.02 - 0.1%, one or more of Ti, Nb, and Zr 0.02 - 0.1% in total and the balance being Fe and incidental impurities. The relationship between tungsten and molybdenum contents of the steel is expressed in the formulated range 12% .ltoreq. W + 2Mo .ltoreq. 16%.

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Yonago, Japan

Norimasa Uchida