JPS59182944A - Hard carbide composite sintered high speed steel and its production - Google Patents

Abstract

PURPOSE:To produce a hard carbide composite sintered high speed steel provided with high tool performance by coating Co or Ni on the powder particles of a hard carbide such as Cr3C2 or the like, mixing a suitable amt. thereof with high speed steel powder, and sintering the mixture under an adequate sintering condition. CONSTITUTION:Co or Ni is coated on the particles of the powder of a hard carbide such as Cr3C2, Mo2C, WC, VC, NbC, TaC, TiC, ZrC, HfC or the like, and 10-50wt% the coated powder and is mixed with 90-50% high speed steel powder to obtain a raw material for sintering. The raw material for sintering is compression molded under a pressure of 5-10t/cm<2> and is sintered in a vacuum or under atm. pressure at 1,200-1,300 deg.C or is subjected to pressure heating and sintering under 3-8t/cm<2> and at 1,200-1,300 deg.C or to hot hydrostatic pressure heating and sintering. The hard carbide composite sintered high speed steel in which the Co or Ni film and the high speed steel particles are sintered to each other and the sintered structure thereof is sintered to the hard carbide particles, is thus obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention uses a mixed powder in which hard carbide powder coated with cobalt or nickel is added to high speed steel powder as a raw material for sintering to produce sintered high speed steel composited with hard carbide. The present invention relates to a method for manufacturing.

As the hard carbide in the hard carbide powder coated with cobalt or nickel, chromium carbide, molybdenum carbide, tungsten carbide, vanadium carbide, niobium carbide, tantalum carbide, titanium carbide, zirconium carbide, and hafnium carbide are used. Individual particles of such hard carbide powder can be coated with cobalt or nickel using known methods such as electroplating or sintering.

The method for producing hard carbide composite sintered high-speed steel of the present invention involves coating the surfaces of individual particles in hard carbide powder with cobalt and nickel, which have the property of sintering well with hard carbides, to increase the hardness of the hard carbide powder. The cobalt or nickel film covering the carbide particles is sintered into hard carbide particles in the sintering process and is also sintered with the high speed steel particles in the high speed steel powder, so that the hard carbide powder and the high speed steel are sintered. Individual orange hard carbide particles in a mixed state with powder and individual high speed steel particles are sintered using a cobalt film or nickel film covering the hard carbide particles as a sintering medium. The method is characterized in that a composite sintered structure is produced by performing the following steps.

As explained above, the present invention uses cobalt-coated hard carbide powder or nickel-coated hard carbide powder in which the surface of hard carbide particles is coated with cobalt or nickel, which has the property of sintering well into hard carbide. A hard carbide characterized in that a mixed powder added to the powder is used as a sintering raw material, and the sintering raw material thus prepared is sintered at a sintering temperature suitable for high-speed steel. Provides an effective method for producing composite sintered high-speed steel, and provides a hard carbide composite sintered high-speed steel with significantly higher tooling performance compared to sintered high-speed steel made from sintered high-speed steel powder. The purpose is to provide.

Next, the process and operation of manufacturing hard carbide composite sintered high-speed steel by the method of the present invention will be explained, as well as the manufactured hard carbide composite sintered high-speed steel.

Sintering raw materials used to produce hard carbide composite sintered high-speed steel include chromium carbide, molybdenum carbide, tungsten carbide, vanadium carbide, zirconium carbide, hafnium carbide, titanium carbide, niobium carbide, and tantalum carbide. 10 cobalt-coated hard carbide powders or nickel-coated hard carbide powders in which cobalt or nickel is coated on the surface of each individual particle of the selected hard carbide powder.
A mixed powder is used in which a proportion of high speed steel powder is selected from a proportion range of 90% to 50% by weight and 90% to 50% by weight. In the sintering process of producing hard carbide composite sintered high-speed steel by sintering the sintering raw material prepared in this way, a sintering method suitable for the intended use of the product and the sintering raw material used is adopted. ,5 tons/
A molded body compression molded using a pressure within the range of crl to 10 ton/crl is heated to 1.200°C to 1.3°C.
Sintering is performed in a vacuum using a sintering temperature within the range of 00°C, or sintering is performed in an atmosphere of reducing gas such as hydrogen gas, or 3 ton/crl to 8 ton /
Sintering pressure within the range of crl and 1.200 °C to 1
．． A sintered body is produced by performing pressure heating sintering using a sintering pressure within the range of 300° C. or by performing hot isostatic pressing heating sintering. The sintered body obtained by sintering by any of these methods consists of cobalt coating individual particles of cobalt-coated hard carbide powder mixed with high speed steel powder in the sintering raw material. The nickel coating covering the individual particles of the coating or nickel-coated hard carbide powder and the individual particles of the high speed steel powder undergo liquid phase sintering to produce a sintered structure, and the sintered structure This is a hard carbide composite sintered high-speed steel in which the hard carbide particles in the cobalt-coated hard carbide particles or the hard carbide particles in the individual nickel-coated hard carbide particles are sintered to form a composite sintered structure.

Next, the work of manufacturing a hard carbide composite sintered high-speed steel and the hard carbide composite sintered high-speed steel of the present invention obtained by manufacturing will be described in accordance with Examples. The cobalt-coated hard carbide powder or nickel-coated hard carbide powder used in this example was a product of Showa Denko, and the high-speed steel powder was a product of Mitsubishi Steel.

Example 1゜The raw material for sintering was a mixed powder in which 50% by weight of high-speed steel powder and 50% by weight of cobalt-coated tungsten carbide powder coated with 12% by weight of cobalt were mixed. used. The mixed powder thus prepared was compression molded using a mechanical press at a pressure of 10 tons/crl to produce a molded body. The molded body is heated to 1.280℃ in a vacuum.
A sintered body was produced by heating for 30 minutes using a sintering temperature of . The resulting sintered body consists of a cobalt film covering each cobalt-coated tungsten carbide particle of the cobalt-coated tungsten carbide powder mixed with high-speed steel powder in the raw material, and a cobalt film covering each cobalt-coated tungsten carbide particle, and each high-speed steel particle. are liquid-phase sintered to form a sintered structure, and the sintered structure is liquid-phase sintered to each individual tungsten carbide particle in each cobalt-coated tungsten carbide particle to form a composite sintered structure. It was a hard carbide composite sintered high speed steel consisting of a tungsten carbide composite sintered high speed steel whose composite sintered structure was tungsten carbide.

Example 2 As a raw material for sintering, a mixed powder was used in which 60% by weight of high-speed steel powder and 40% by weight of dimolybdenum carbide powder coated with 12% by weight of cobalt were mixed. .

Using a mechanical press, 10 t of the mixed powder prepared in this manner was
A molded body was produced by compression molding at a pressure of on/crl. The compact was heated in vacuum at a temperature of 1.280°C for 30 minutes to produce a sintered body. The resulting sintered body consists of a cobalt film covering each dimolybdenum carbide particle of cobalt-coated dimolybdenum carbide powder mixed with high-speed steel powder in the raw material mixed powder, and a cobalt film covering each individual dimolybdenum carbide particle and each high-speed steel powder. The steel particles are liquid-phase sintered to form a sintered structure, and the sintered structure is liquid-phase sintered to each individual dimolybdenum carbide particle in each cobalt-coated dimolybdenum carbide particle to form a composite sintered structure. It was a hard carbide composite sintered high-speed steel made of dimolybdenum carbide composite sintered high-speed steel, which constitutes a composite sintered structure.

Example 3 A mixed powder prepared by mixing 60% by weight of high-speed steel powder and 40% by weight of titanium carbide powder coated with 25% by weight of nickel was used as a raw material for sintering. The raw material for sintering prepared in this way was pressed into 11 pieces using a cold isostatic press.
A molded body was produced by compression molding at a pressure of 1 ton/crl. The molded body was heated for 1.2 hours in a hydrogen gas atmosphere.
Liquid phase sintering was performed by heating at a temperature of 70° C. for 30 minutes to produce a sintered body. The resulting sintered body consists of a nickel film covering each titanium carbide particle of the nickel-coated titanium carbide powder that was mixed with the high-speed steel powder in the mixed powder of the sintering raw material, and a nickel film covering each titanium carbide particle and each high-speed steel powder. The speed steel particles are liquid-phase sintered to form a sintered structure, and the sintered structure is liquid-phase sintered to each individual titanium carbide particle in each nickel-coated titanium carbide particle to form a composite sintered structure. It was a hard carbide composite sintered high-speed steel consisting of a titanium carbide composite sintered high-speed steel, which is a composite sintered structure.

Example 4 The raw materials for sintering include 60% by weight of high-speed steel powder and 4% by weight of vanadium carbide powder coated with 16% by weight of cobalt.
A mixed powder mixed at a ratio of 0% by weight was used. The raw materials for sintering prepared in this way were processed using a cold isostatic press.
A molded body was produced by compression molding at a pressure of 0 ton/crl.

The molded body was heated in a vacuum at a temperature of 1.270°C for 3
A sintered body was produced by heating for 0 minutes to perform liquid phase sintering. The resulting sintered body consists of a cobalt film covering each vanadium carbide particle of the cobalt-coated vanadium carbide powder mixed with high-speed steel powder in the mixed powder of the raw material for sintering, and a cobalt film covering each vanadium carbide particle. The high-speed steel particles undergo liquid phase sintering to form a sintered structure, and the sintered structure is liquid phase sintered to individual vanadium carbide particles in individual cobalt-coated vanadium carbide particles to form a composite sintered structure. It was a hard carbide composite sintered high-speed steel consisting of vanadium carbide composite sintered high-speed steel, which constituted the composite sintered body.

Example 5゜The raw material for sintering was a mixed powder in which 70% by weight of high-speed steel powder and 30% by weight of chromium carbide powder coated with 16% by weight of cobalt were mixed. . The raw material for sintering prepared in this manner was subjected to a hydrostatic pressure of 8 ton/cd using a hot isostatic pressure heating device, and at the same time 1.27 ton/cd of hydrostatic pressure was applied.
Liquid phase sintering was performed by heating at a temperature of 0° C. for 30 minutes to produce a sintered body. The produced sintered body includes a cobalt film covering silicon carbide particles in individual particles of cobalt-coated chromium carbide powder mixed with high-speed steel powder in the mixed powder of the raw material for sintering; Individual high-speed steel particles are liquid-phase sintered to form a sintered structure, and the sintered structure is liquid-phase sintered to individual chromium carbide particles in individual cobalt-coated chromium carbide particles to form a composite sintered structure. It was a hard carbide composite sintered high-speed steel consisting of a chromium carbide composite sintered high-speed steel, which constituted a compact structure, and the composite sintered structure constituted by the composite sintered structure.

When the hard carbide composite sintered high-speed steel produced in the examples described above was tempered at a temperature of 570° C., the hardness was HRC 6B to 69.

The high-speed steel powder used in the examples was compression-molded using a mechanical press at a pressure of 8 ton/ca, and the compact was sintered at a temperature of 1,230°C in a vacuum at a temperature of 570°C. The hardness is HRC65 when tempered at a temperature of
showed that. That is, the hard carbide composite sintered high-speed steel manufactured in the examples was obtained by sintering the high-speed steel powder used as a component in the sintering raw material for manufacturing the hard carbide composite sintered high-speed steel. It was found that the stirrup was a sintered steel material with a significantly higher height than the obtained sintered high-speed steel.

Claims (2)

[Claims] (1) Individual particles of hard carbide powder selected from chromium carbide, molybdenum carbide, tungsten carbide, vanadium carbide, niobium carbide, tantalum carbide, titanium carbide, zirconium carbide, and hafnium carbide are coated with cobalt or nickel. 10% to 5% by weight of cobalt-coated hard carbide powder or nickel-coated hard carbide powder.
0 wt% and 90 wt% to 50 wt% high speed steel powder.
A mixed powder mixed in a ratio selected from within the ratio range is used as a raw material for sintering, and the raw material for sintering is
A sintered body sintered at a temperature in the range of 0°C to 1.300°C, the cobalt coating on a large number of cobalt-coated hard carbide particles or the nickel on nickel-coated hard carbide particles in the sintering raw material. The coating and a large number of high-speed steel particles are mutually sintered to form a sintered structure, and the sintered structure is composed of hard carbide particles in individual cobalt-coated hard carbide particles or individual nickel-coated particles. A hard carbide composite sintered high-speed steel characterized in that hard carbide particles are sintered with hard carbide particles to form a composite sintered structure. (2) Individual hard carbide particles of hard carbide powder selected from chromium carbide, molybdenum carbide, tungsten carbide, vanadium carbide, niobium carbide, tantalum carbide, titanium carbide, zirconium carbide, and hafnium carbide are coated with cobalt or nickel. 10% to 50% by weight of cobalt-coated hard carbide powder or nickel-coated hard carbide powder, and 90% to 5% by weight of high-speed steel powder.
A mixed powder mixed in a ratio selected from within the ratio range of 0% by weight was used as the raw material for sintering, and the raw material for sintering was 5 tons.
/ctl to 10ton/c4 The molded body was compression molded using a pressure in the range of 1.200℃ to 1.300℃.
Vacuum sintering or pressureless sintering using a temperature in the range of °C, or a pressure in the range of 3 ton/crl to 8 ton/ca and a pressure in the range of 1,200 °C to 1,300 °C. 1. A method for producing a hard carbide composite sintered high-speed steel, the method comprising performing pressure heating sintering using or hot isostatic pressure pressing heating sintering to produce a composite sintered structure.