JPS601381B2 - Cutting tool material with excellent high temperature properties - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a cutting tool material that has excellent high-temperature properties and exhibits excellent performance particularly when used in high-speed cutting and high-feed cutting that require these properties. Generally, when cutting steel, when the cutting speed is increased or the feed rate is increased, the temperature of the cutting tool's cutting edge increases, and the cutting tool reaches the end of its useful life due to plastic deformation caused by the high temperature rather than wear. In many cases, this tendency is becoming stronger due to recent advances in high-speed cutting and high-efficiency cutting. However, tungsten carbide and titanium carbide, which are currently in practical use, have a hard phase, and iron group metals (Fe, N,
Cemented carbides and cermets with Co) as a binder phase suddenly soften when the cutting edge temperature exceeds 1000 qC. The conditions for use of the formed surface-coated cemented carbide and surface-coated cermet are limited to a cutting edge temperature of slightly over 1000°C.
Among these, ceramics whose main component is aluminum oxide are used as high-speed cutting tools because they exhibit high hardness and excellent oxidation resistance at high temperatures. In reality, it is used only under conditions of low feed rate because it is prone to chipping and has insufficient reliability. Therefore, from the above-mentioned viewpoint, the present inventors conducted research to obtain a material for cutting tools that has excellent high-temperature properties and is capable of high-speed cutting and high-feed cutting. A compound phase containing as a main component a compound phase containing one or two of Zr and Hf as a main component, and a compound phase containing one or two of Nb and Ta as a main component. If the structure is composed of three phases, and the binder phase is a high melting point metal phase mainly composed of W, it exhibits high hardness, high ballability, and excellent oxidation resistance at high temperatures, resulting in stability. This enables high-speed cutting and high-feed cutting, and this structure
Ti: 2.5-34.0%, one of Zr and Hf
Species or two: 3.7 to 64.0%, One or two of Nb and Ta: 1 to 38%, Oxygen: 0.01 to
1.3%, C: 0.8-9.3%, Nitrogen: 0.01-3
．． 3%, the rest basically consists of W and unavoidable impurities, and the conditional formula: [TW(Zr, Hf
)x(Nb, Ta)yW, -w-x-y]・[0uNv
C, -u-v]Z (however, w/(w+x): 0.3-0
．． &(w + x y): 0.3~0.8, y: 0.01~
0.2, u: 0.005-0.1, v: 0.005-0
．． z: 0.2 to 0.7). When tb-mi contains Mo in the range of 1 to 18%, the specific gravity and cost of the material can be reduced without impairing the material properties. (C} Furthermore, when one or more of the iron group metals (Fe, Ni, Co) is combined in a range of 1 to 5%, the silk-sintering properties are further improved. The above findings shown in {a} to (c) have been obtained. This invention has been made based on the above findings, and the reason for limiting the component composition and conditional expressions as above is explained below. Explain.A Component composition {a- Tj Ti combines with carbon, nitrogen, oxygen, etc. to form a compound phase, which is one of the three phases that make up the hard phase, and imparts high hardness to the material. Ti has the effect of improving the wear resistance of the material, but if its content is less than 2.5%, the desired amount of fine Ti is removed during the cooling process from the intermittent state in the striping process. The compound phase, which is the main component, does not precipitate and separate, and therefore high hardness cannot be ensured; on the other hand, 34.0%
If the content exceeds 2.0%, the hard phase will become too large and the quality will deteriorate, so the content should be reduced to 2.0%.
It was set at 5 to 34.0%. 'b} Zr and Hf Like Ti, these components combine with carbon, nitrogen, oxygen, etc. to form a compound phase, which is one of the three phases that make up the hard phase, and improve the wear resistance of the material. However, when the content is less than 3.7%, a predetermined amount of compound phase mainly composed of Zr and Hf does not precipitate and separate (from the Ti-based compound phase) upon cooling from the solid solution state. Zr and/
(or, if the Hf-based compound phase precipitates at the same time, the hard phase becomes fine), therefore, high hardness cannot be imparted to the material.On the other hand, if the content exceeds 64.0%,
Like i, it causes toughness deterioration, so its content was set at 3.7 to 64.0%. 'c} Nb and Ta These components also form a compound phase, which is one of the three phases that make up the hard phase, like Ti, Zr, and Hf, and have the effect of significantly improving oxidation resistance in particular. If the content is less than 1%, the desired excellent oxidation resistance cannot be ensured, while if the content exceeds 31%, the quality will decrease. It was set at 1% to 31%. {d) Oxygen As mentioned above, oxygen combines with Ti, Zr, m, Nb, and Ta to form a compound phase, and in particular forms carbonitride oxides, which has the effect of increasing the hardness and oxidation resistance of the material. However, if the content is less than 0.01%, the amount of carbonitride becomes relatively large, which increases the ability to bond with the workpiece during cutting and deteriorates wear resistance. If the content exceeds 3%, the hard phase tends to become coarse, resulting in poor rutting properties and a decrease in hardness, so the content should be reduced to 0.
It was set at 01 to 1.3%. 'e} Carbon As mentioned above, carbon combines with Ti, Zr, Hf, Nb, Ta, and in some cases W to form carbides and carbonitride oxides that constitute a hard phase, which improves wear resistance and oxidation resistance. However, if its content is less than 0.8%, it will not be possible to secure a hard phase with the specified amount and hardness, while if it is contained in excess of 9.3%, it will have a relatively Since the proportion of the binder phase becomes too small compared to the hard phase and the toughness deteriorates, the content was set at 0.8 to 9.3%.

[f} Like nitrogen, nitrogen is Ti, Zr, m, Nb, T
It combines with a to form a compound phase, which has the effect of improving the wear resistance and oxidation resistance of the material, but if the content is 0.
If it is less than 0.01%, the desired amount of carbonitoxide cannot be formed, and as a result, it will become welded to the machinability during cutting and wear will progress significantly, while if it exceeds 3.3%. If the content reaches 0.01% to 3.3%, the hard phase becomes coarser and the hardness of the material decreases again. (9 Mo The Mo component has the effect of lowering the specific gravity of the material and relatively lowering the W content without impairing the properties of the material, thereby reducing costs.
If the content is less than 1%, the desired effect cannot be obtained, while if the content exceeds 18%, the high-temperature properties will deteriorate overall. %. (h) Iron group metals Iron group metals have the effect of further improving the firing properties of materials, but if their content is less than 1%, the desired effect of improving the properties of iron can not be obtained; If the content exceeds this amount, the high-temperature properties will deteriorate, so the content was set at 1 to 5%. B When the atomic ratio of the atomic ratio (w + x + y) of the conditional expression {a' (w + x + y) is less than 0.3, the amount of the hard phase becomes too small compared to the binder phase and the desired high hardness, that is, excellent On the other hand, if the atomic ratio exceeds 0.8, the amount of binder phase becomes too small to ensure the desired high toughness. Since it becomes impossible to 8. [b} Atomic ratio of w/(w+x) When the ratio of w/(w+x) is less than 0.3 in terms of atomic ratio, the amount of precipitated compound phase mainly composed of Ti is relatively smaller than that of Zr and/or Tj-based compounds and Z, which are too small compared to the compound phase mainly composed of Hf and contribute to the refinement of the hard phase.
The coexistence of r and/or Hf-based compounds becomes virtually impossible, and as a result, the hard phase becomes mainly a compound phase mainly composed of Zr, Hf, Nb, and Ta, making it impossible to maintain the fine structure. causing a decrease in hardness and toughness,
On the other hand, if this ratio exceeds 0.8, the amount of the compound phase mainly composed of Zr and/or Hf becomes too small compared to the compound phase mainly composed of Ti, and for the same reason, the amount of the compound phase mainly composed of Zr and/or Hf becomes too small. Since it becomes impossible to secure the structure, the atomic ratio is set to 0.3 to 0.0. 8. {C} When the atomic ratio of y is less than 0.01, the amount of the Nb and/or Ta-based compound phase is too small to ensure the desired excellent oxidation resistance as described above. On the other hand, if the atomic ratio exceeds 0.2, the rutting property will substantially deteriorate, so the atomic ratio was set at 0.01 to 0.2. {Atomic ratio of d'u When the atomic ratio of u is less than 0.005, the oxygen content in the compound phase constituting the hard phase becomes too low compared to the carbon content and nitrogen content, resulting in oxygen deficiency. If the ratio exceeds 0.1, the amount of oxygen will be large compared to carbon and nitrogen. The atomic ratio was determined to be 0.005 to 0.1 because if it is too high, the hard phase becomes coarse and it becomes impossible to secure the desired high hardness and high sardine properties. {e] Atomic ratio of v If the atomic ratio of v is less than 0.005, the nitrogen content in the compound phase constituting the hard phase will be too low compared to the carbon content and oxygen content, and the carbon This is because the formation of oxides becomes insufficient, making it difficult to ensure high hardness, and on the other hand, if this ratio exceeds 0.3, the hard phase becomes coarser, resulting in a decrease in hardness. , the atomic ratio was determined to be 0.005 to 0.3. 'f} Atomic ratio of z This value determines the ratio of Ti, Zr, Hf, Nb, Ta, Mo and iron group metals contained as necessary, and carbon, nitrogen, and oxygen. If this value is less than 0.2%, the amount of hard phase will be relatively too small, making it impossible to secure the desired high hardness and oxidation resistance, while if this value exceeds 0.7, If the amounts of carbon, nitrogen, and oxygen become too large, even the W constituting the binder phase will form carbides, resulting in an insufficient amount of the binder phase and the ballability will deteriorate. was determined to be 0.2 to 0.7.Next, the material for cutting tools of the present invention will be specifically explained using examples.As the raw material powder of the example, T°C powder with an average particle size of 1.0 French was used. (contains 0.3% oxygen), TIN powder (contains 1.1% oxygen),
(contains 0.3%), powder (oxygen: 0.
2%), HfC powder (oxygen: 0.1
(containing 5%), NbC powder (oxygen: 0.2
%), 1.0 French TaC powder (oxygen: 0.15
(contains 0.8%), W powder (contains 0.05% oxygen), 0.8% Mo powder (contains 0.1% oxygen).
, Fe powder (containing 0.4% oxygen) at 2.0 mm, Ni powder (containing 0.3% oxygen) at 1.1 mound, and Co powder (containing 0.3% oxygen) at 1.0 mound. (containing 0.3%), blend these raw powders in a predetermined ratio, mix in a ball mill, press at a pressure of 1000k9' to form a green compact, and then press this powder into a 1oo ~10-2to
After holding for 1 hour at temperature: 210,000 in vacuum with a pressure of
By cooling at a cooling rate of qC/hr, the material of the present invention having the final component composition and conditional formula substantially shown in Table 1 (in the formula of Table 1, M is Mo, Fe, Ni, Co) Comparative Materials 1 to 23 and Comparative Materials 1 to 12 were manufactured, respectively. It should be noted that Comparative Materials 1 to 12 all have a composition in which one of the constituent components (indicated by * in Table 1) is outside the scope of the present invention. The Rockwell hardness (A scale) and transverse rupture strength of the obtained materials 1 to 23 of the present invention and comparative materials 1 to 12 were measured, and a cutting tip with a shape of SNP432 was taken out from them and the work material : SNCM-8 (HB320), cutting speed: 150/min, depth of cut: 2 pigs, feed: 0.7
side/rev. A cutting test was conducted under the following conditions, and the cutting time until flank wear reached 0.3 was measured, and the state of the cutting edge was also observed. These results are summarized in Table 2. From the results shown in Table 2, Materials 1 to 23 of the present invention all have high hardness and high quality, and exhibit excellent cutting performance. Therefore, Comparative Materials 1 to 12 are inferior in at least one of these properties. As mentioned above, the material of the present invention has high hardness, high quality, and excellent oxidation resistance, and these characteristics are
Since the hard phase has a fine three-phase structure and the binder phase is composed of a metal phase whose main component is W, which is a high melting point metal, it can be used even at high temperatures. It has industrially useful properties such as stably exhibiting excellent cutting performance over a long period of time even when high-speed cutting and high-feed cutting are applied.

Claims (1)

[Claims] 1 Ti: 2.5 to 34.0%, one or two of Zr and Hf: 3.7 to 64.0%, Nb and T
One or two of a: 1 to 31%, oxygen: 0.0
1-1.3%, C: 0.8-9.3%, Nitrogen: 0.01
~3.3%, W and unavoidable impurities: the remainder (hereinafter referred to as wt%), and in atomic ratio, [Tiw(Zr
, Hf)x(Nb, Ta)yW_1_-w_-x_-y
]・[OuNvC_1_-u_-v]z (However, w/
(w+x): 0.3-0.8, (w+x+y): 0.3
~0.8, y: 0.01~0.2, u: 0.005~0
．． 1, v: 0.005-0.3, z: 0.2-0.7)
, and the hard phase is a compound phase containing Ti as a main component, a compound phase containing either or both of Zr and Hf, and either or both of Nb and Ta. A material for cutting tools having excellent high-temperature properties, characterized by having a structure consisting of three fine phases including a compound phase containing W as the main component, and a high melting point metal phase containing W as the main component. 2 Ti: 2.5-34.0%, one or two of Zr and Hf: 3.7-64.0%, Nb and T
One or two of a: 1 to 31%, oxygen: 0.0
1-1.3%, C: 0.8-9.3%, Nitrogen: 0.01
~3.3%, Mo: 1~18%, W and unavoidable impurities: the remainder, and has an atomic ratio of [Tiw(
Zr, Hf) x (Nb, Ta) y (W, Mo)_1_-
w_-x_-y〕・[OuNvC_1_-u_-v]z
(However, w/(w+x): 0.3 to 0.8, (w+x
+y): 0.3-0.8, y: 0.01-0.2, u:
0.005-0.1, v: 0.005-0.3, z: 0
．． 2 to 0.7), and the hard phase is
A fine three-phase compound phase containing Ti as a main component, a compound phase containing either or both of Zr and Hf as a main component, and a compound phase containing either or both of Nb and Ta as a main component. A material for cutting tools having excellent high-temperature properties, characterized in that the binder phase has a composition consisting of a high melting point metal phase mainly composed of w. 3 Ti: 2.5-34.0%, one or two of Zr and Hf: 3.7-64.0%, Nb and T
One or two of a: 1 to 31%, oxygen: 0.0
1-1.3%, C: 0.8-9.3%, Nitrogen: 0.01
~3.3%, one of the iron group metals (Fe, Ni, Co)
Species or two or more: 1-5%, W and inevitable impurities:
It has a composition (by weight%) consisting of the rest, and has an atomic ratio of [Tiw(Zr, Hf) x (Nb, Ta) y (W, F
e, Ni, Co)_1_-w_-x_-y]・[OuN
vC_1_-u_-v]z (however, w/(w+x):
0.3-0.8, (w+x+y): 0.3-0.8, y
:0.01~0.2, u:0.005~0.1, v:0
．． 005 to 0.3, z: 0.2 to 0.7), and the hard phase contains a compound phase mainly composed of Ti and either or both of Zr and Hf. The structure consists of three fine phases: a compound phase containing Nb and/or Ta as a main component, and a compound phase containing either or both of Nb and Ta as a main component, while the binder phase consists of a high melting point metal phase containing w as a main component. A cutting tool material with excellent high-temperature properties. 4 Ti: 2.5 to 34.0%, one or two of Zr and Hf: 3.7 to 64.0%, Nb and T
One or two of a: 1 to 31%, oxygen: 0.0
1-1.3%, C: 0.8-9.3%, Nitrogen: 0.01
~3.3%, Mo: 1~18%, iron group metals (Fe, Ni
, Co): 1 to 5%, W and unavoidable impurities: the remainder (wt%), and has an atomic ratio of [Tiw (Zr, Hf) x ( Nb
, Ta)y(W, Mo, Fe, Ni, Co)_1_-w
＿−x＿−y〕・〔OuNvC_1＿−u＿−v〕z(
However, w/(w+x): 0.3 to 0.8, (w+x+
y): 0.3-0.8, y: 0.01-0.2, u: 0
．． 005-0.1, v: 0.005-0.3, z: 0.
2 to 0.7), and the hard phase is T
A fine three-phase compound phase containing i as a main component, a compound phase containing either or both of Zr and Hf as a main component, and a compound phase containing either or both of Nb and Ta as a main component 1. A material for cutting tools having excellent high-temperature properties, characterized in that the binder phase has a structure consisting of a high melting point metal phase mainly composed of W.